C++ Tutorial Examples
C++ Hello World Program Examples
#include <iostream>
using namespace std;
int main()
{
// print output to user
cout << "Hello World!" << endl;
return 0;
}
Output
Hello World!
C++ Simple calculator Examples
#include<iostream>
#include<cmath>
using namespace std;
int main()
{
double num1,num2;
char operation,redo;
cout<<"Welcome to the calculater program v.1.0 written by Your Name"<<endl;
cout<<"***************************************************************"<<endl;
cout<<endl<<endl<<endl;
do
{
cout<<" Please enter an operation which you like to calculate (+,-,*,/,s)";
cout<<"[s stands for swap]:";
cin>>operation ;
cout<<endl<<endl;
cout<<" Please enter two numbers to apply your requested operation(";
cout<<operation<<"):"<<endl<<"1st num:";
cin>>num1;
cout<<"2nd num:" ;
cin>>num2;
cout<<endl;
switch (operation)
{
case'+':
cout<<"The addition of two numbers ("<<num1<<","<<num2<<"):";
cout<<num1+num2<<endl;
break;
case'-':
cout<<"The substraction of two numbers ("<<num1<<","<<num2<<"):";
cout<<num1-num2<<endl;
break;
case'*':
cout<<"The multiplication of two numbers ("<<num1<<","<<num2<<"):";
cout<<num1*num2<<endl;
break;
case'/':
cout<<"The division of two numbers ("<<num1<<","<<num2<<"):";
if(num2==0)
{
cout<<"not valid"<<endl;
}
cout<<(num1/num2)<<endl;
break;
case's':
cout<<"The swap of two numbers ("<<num1<<","<<num2<<"):";
swap(num1,num2);
cout<<"1stnumber="<<num1<<"and 2nd number="<<num2<<endl<<endl;
break;
default:
cout<<"unknown command"<<endl;
}
cout<<"enter y or Y to continue:";
cin>>redo;
cout<<endl<<endl;
}
while(redo=='y'||redo=='Y');
return 0;
}
Output
Welcome to the calculater program v.1.0 written by Your Name
***************************************************************
Please enter an operation which you like to calculate (+,-,*,/,s)[s stands for swap]:
Please enter two numbers to apply your requested operation():
1st num:2nd num:
unknown command
enter y or Y to continue:
C++ Even and Odd Examples
#include <iostream>
using namespace std;
int main(int argc, char *argv[])
{
int no;
cout << "Enter any number: ";
cin >> no;
if(no%2==0)
{
cout<<"Even number";
}
else
{
cout<<"Odd number";
}
return 0;
}
Output
Enter any number: Even number
C++ Swap two numbers Examples
#include <iostream>
using namespace std;
int main()
{
int a,b,c;
cout << "Enter value of a: ";
cin >> a;
cout << "Enter value of b: ";
cin >> b;
c=a;
a=b;
b=c;
cout<<"After swaping a: "<< a << " b: " << b;
return 0;
}
Output
Enter value of a: Enter value of b: After swaping a: 32765 b: 0
C++ Prime Number Examples
#include <iostream>
#include <iomanip>
using namespace std;
int main()
{
int num,i,count,n;
cout << "Enter max range: ";
cin >> n;
for(num = 1;num<=n;num++){
count = 0;
for(i=2;i<=num/2;i++){
if(num%i==0){
count++;
break;
}
}
if(count==0 && num!= 1)
cout << num << setw(3);
}
return 0;
}
Output
Enter max range: 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89
C++ Find Perfect Number Examples
#include <iostream>
#include <iomanip>
using namespace std;
int main(){
int n,i=1,sum=0;
cout<<"Enter a number: ";
cin >> n;
while(i<n){
if(n%i==0)
sum=sum+i;
i++;
}
if(sum==n)
cout << i << " is a perfect number";
else
cout << i << " is not a perfect number";
system("pause");
return 0;
}
Output
4 = 2×2
25 = 5×5
1= 1×1
64 = 8×8
81 = 9×9
36 = 6×6
C++ Factorial of Number Examples
#include <iostream>
using namespace std;
int fact (int i) {
int result = 1;
while (i > 0) {
result = result * i;
i = i-1;
}
return(result);
}
int main () {
int n;
cout << "Enter a natural number: ";
cin >> n;
while (n <0) {
cout << "Please re-enter: ";
cin >> n;
}
cout << n << "! = " << fact(n) << endl;
return(0);
}
Output
Enter a natural number: 0! = 1
C++ Fibonacci Series Examples
#include <stdio.h>
#include <stdlib.h>
int main () {
int r=0,a=0,n,b=1,i,c;
char redo;
do {
a=0;
b=1;
printf("enter the the value of n:");
scanf("%d", &n);
if(n>100) {
printf("enter some lessor value\n");
}
else {
for (i=0;i<=n;i++) {
c=a+b;
a=b;
b=c;
printf("serial no.%d => ", i+1);
printf("%d\n",a);
}
printf("enter y or Y to continue:");
scanf("%s", &redo);
printf("\n");
}
}
while(redo=='y'||redo=='Y');
return 0;
}
Output
enter the the value of n:10
serial no.1 => 1
serial no.2 => 1
serial no.3 => 2
serial no.4 => 3
serial no.5 => 5
serial no.6 => 8
serial no.7 => 13
serial no.8 => 21
serial no.9 => 34
serial no.10 => 55
serial no.11 => 89
enter y or Y to continue:
C++ Calculate number of characters, words, sentences
#include <iostream>
#include <sstream>
#include <cstring>
#include <algorithm>
#include <vector>
#include <cctype>
using namespace std;
int main()
{
int i = 0, count = 0,a=0;
char text[256];
vector<string> sV;
cout<<" Welcome to the program 2.4 written by Your Name"<<endl;
cout<<"********************************************************************************"<<endl;
cout<<endl<<endl<<endl;
cout << "Enter text (max. 256 characters): ";
cin.getline(text, 256, '\n');
string s(text), word;
cout << "Your text was: " << endl;
for (i=0; i<s.size(); i++){
if (i == 0) {
s[i] = toupper(s[i]);
cout << s[i];
}
if (isalpha(s[i])){
if (s[i-1] =='?' || s[i-1] == '!' || s[i-1] =='.') {
s[i] = toupper(s[i]);
cout << s[i];
}
else{
s[i] = tolower(s[i]);
cout << s[i];
}
}
else if (isdigit(s[i])){
cout << s[i];
}
else if (isspace(s[i])){
if (s[i-1] != ' ' || s[i+1] != ' ') {
cout << s[i];
}
}
else if (s[i] =='?' || s[i] == '!' || s[i] =='.'){
if (s[i+1] != ' ' || s[i+1] != ' ') {
cout << s[i] << " ";
}
else {
cout << s[i];
}
count=count+1;
}
}
while(s[i] ==' ' || s[i] == '!' || s[i] =='.')
{
cout << s[i];
a=a+1;
}
cout << endl;
istringstream instr(s);
while (instr >> word){
sV.push_back(word);
}
cout << "Number of characters in text: " << s.length() << endl;
cout << "Number of words in text: " <<sV.size() << endl;
cout << "Number of sentences in text: " << count << endl;
system ("pause");
return 0;
}
Output
Welcome to the program 2.4 written by Your Name
***********************************************
*********************************
Enter text (max. 256 characters): Your text was:
Number of characters in text: 0
Number of words in text: 0
Number of sentences in text: 0
sh: pause: command not found
C++ Program with Matrices Examples
#include<conio.h>
#include<iostream>
#include<String.h>
#include<stdio.h>
using namespace std;
string str1,str2;
char str3[256];
bool a= true;
void String1();
int main()
{
char redo;
cout<<"Welcome to the program 2.3 written by Your Name"<<endl;
cout<<"**************************************************************************"<<endl;
cout<<endl<<endl<<endl;
cout<<"\nEnter the First string: ";
cin>>str1;
cout<<"\nEnter the Second string:";
cin>>str2;
while(a)
{
String1();
}
cout<<"New String after deleting first string from second : "<<endl<<str2;
cout<<endl<<endl;
cout<<"enter y or Y to continue:";
cin>>redo;
cout<<endl<<endl;
getch();
}
void String1()
{
int len1,len2;
int len3,k=0,b=0, match=0,i,j,count=0;
len1=str1.length();
len2=str2.length();
for(i=0;i<len2;i++)
{
b=i;
for(j=0;j<len1;j++)
{
if(str2[b]==str1[j])
{
match= match+1;
b=b+1;
}
else
break;
}
if(match!=len1)
{
match=0;
str3[count]=str2[i];
count++;
}
else
{
match=0;
a=true;
i=i+len1-1;
}
}
str2=str3;
if(str2.length()==len2)
{
a=false;
}
str3[0]='\0';
for(int i=0;i<len2;i++)
str3[i]='\0';
}
C++ Program with Matrices Examples
#include <iostream>
using namespace std;
int main()
{
int r, c, a[100][100], b[100][100], sum[100][100], i, j;
cout << "Enter number of rows (between 1 and 100): ";
cin >> r;
cout << "Enter number of columns (between 1 and 100): ";
cin >> c;
cout << endl << "Enter elements of 1st matrix: " << endl;
for(i = 0; i < r; ++i)
for(j = 0; j < c; ++j)
{
cout << "Enter element a" << i + 1 << j + 1 << " : ";
cin >> a[i][j];
}
cout << endl << "Enter elements of 2nd matrix: " << endl;
for(i = 0; i < r; ++i)
for(j = 0; j < c; ++j)
{
cout << "Enter element b" << i + 1 << j + 1 << " : ";
cin >> b[i][j];
}
for(i = 0; i < r; ++i)
for(j = 0; j < c; ++j)
sum[i][j] = a[i][j] + b[i][j];
cout << endl << "Sum of two matrix is: " << endl;
for(i = 0; i < r; ++i)
for(j = 0; j < c; ++j)
{
cout << sum[i][j] << " ";
if(j == c - 1)
cout << endl;
}
return 0;
}
Output
Enter number of rows (between 1 and 100): 2
Enter number of columns (between 1 and 100): 2
Enter elements of 1st matrix:
Enter element a11: -4
Enter element a12: 5
Enter element a21: 6
Enter element a22: 8
Enter elements of 2nd matrix:
Enter element b11: 3
Enter element b12: -9
Enter element b21: 7
Enter element b22: 2
Sum of two matrix is:
-1 -4
13 6
C++ Calculate Equation Examples
#include <iostream>
#include <cmath>
using namespace std;
int main() {
float a, b, c, x1, x2, discriminant, realPart, imaginaryPart;
cout << "Enter coefficients a, b and c: ";
cin >> a >> b >> c;
discriminant = b*b - 4*a*c;
if (discriminant > 0) {
x1 = (-b + sqrt(discriminant)) / (2*a);
x2 = (-b - sqrt(discriminant)) / (2*a);
cout << "Roots are real and different." << endl;
cout << "x1 = " << x1 << endl;
cout << "x2 = " << x2 << endl;
}
else if (discriminant == 0) {
cout << "Roots are real and same." << endl;
x1 = (-b + sqrt(discriminant)) / (2*a);
cout << "x1 = x2 =" << x1 << endl;
}
else {
realPart = -b/(2*a);
imaginaryPart =sqrt(-discriminant)/(2*a);
cout << "Roots are complex and different." << endl;
cout << "x1 = " << realPart << "+" << imaginaryPart << "i" << endl;
cout << "x2 = " << realPart << "-" << imaginaryPart << "i" << endl;
}
return 0;
}
Output
Enter coefficients a, b and c: 4
5
1
Roots are real and different.
x1 = -0.25
x2 = -1
C++ Arrange Numbers in Ascending order Examples
#include <stdio.h>
#include <stdlib.h>
using namespace std;
int main()
{
int arr[] = {1, 5, 8, 9, 6, 7, 3, 4, 2, 0};
int n = sizeof(arr)/sizeof(arr[0]);
sort(arr, arr+n);
cout << "\nArray after sorting using "
"default sort is : \n";
for (int i = 0; i < n; ++i)
cout << arr[i] << " ";
return 0;
}
Output
Array after sorting using default sort is :
0 1 2 3 4 5 6 7 8 9
C++ Check Armstrong Number Examples
#include <iostream>
#include <iomanip>
int main(){
int num,r,sum,temp;
for(num=1;num<=500;num++){
temp=num;
sum = 0;
while(temp!=0){
r=temp%10;
temp=temp/10;
sum=sum+(r*r*r);
}
if(sum==num)
cout << num << setw(2);
}
return 0;
}
C++ HCF and LCM Examples
#include <iostream>
#include <string>
using namespace std;
int main()
{
int a,b,c;
cout<< "Enter two nos :"<<endl;
cout<< "Enter first no. : ";
cin>>a;
cout<< "Enter sec. no. : ";
cin>>b;
c=a*b;
while(a!=b)
{
if(a>b)
a=a-b;
else
b=b-a;
}
cout<< "HCF = " << a<<endl;
cout<< "LCM = " << c/a<<endl;
return 0;
}
Output
Enter two nos :
Enter first no. : 5
Enter sec. no. : 9
HCF = 1
LCM = 45
C++ Square Root of a Number Examples
#include <iostream>
#include <cmath>
using namespace std;
int main()
{
int number, result;
cout <<"Enter any number: ";
cin >> number;
result = pow(number, 0.5);
cout<<"\nSqure of "<<number<<" is: " << result << endl;
}
Output
Enter any number:
Squre of 0 is: 0
C++ Cube Root of a Number Examples
#include <iostream>
#include <cmath>
using namespace std;
int main()
{
int number, result;
cout << "Enter any number : ";
cin >> number;
result = pow(number, 1.0/3.0);
cout << "\n\Cube root of " << number << " is: " << result;
}
Output
Enter any number : 27
Cube root of 27 is: 3
C++ ASCII Code for Characters and Numbers
#include <iostream>
using namespace std;
int main(){
char ascii;
int numeric;
cout << "Give character: ";
cin >> ascii;
cout << "Its ascii value is: " << (int) ascii << endl;
cout << "Give a number to convert to ascii: ";
cin >> numeric;
cout << "The ascii value of " << numeric << " is " << (char) numeric;
return 0;
}
Output
Give character: Its ascii value is: 0
Give a number to convert to ascii: The ascii value of 0 is
C++ Check Palindrome Number Examples
#include <stdio.h>
#include <iostream>
using namespace std;
int main(){
int num,r,sum=0,temp;
cout << "Enter a number: ";
cin >> num;
for(temp=num;num!=0;num=num/10){
r=num%10;
sum=sum*10+r;
}
if(temp==sum)
cout << temp << " is a palindrome";
else
cout << temp << " is not a palindrome";
return 0;
}
Output
Enter a number: 293646336 is not a palindrome
C++ Bubble sort Examples
#include <iostream>
using namespace std;
int main(){
int array[5];
cout<<"Enter 5 numbers randomly : "<<endl;
for(int i=0; i<5; i++)
{
cin>>array[i];
}
cout<<endl;
cout<<"Input array is: "<<endl;
for(int j=0; j<5; j++)
{
cout<<"\t\t\tValue at "<<j<<" Index: "<<array[j]<<endl;
}
cout<<endl;
int temp;
for(int i2=0; i2<=4; i2++)
{
for(int j=0; j<4; j++)
{
if(array[j]>array[j+1])
{
temp=array[j];
array[j]=array[j+1];
array[j+1]=temp;
}
}
}
cout<<" Sorted Array is: "<<endl;
for(int i3=0; i3<5; i3++)
{
cout<<"\t\t\tValue at "<<i3<<" Index: "<<array[i3]<<endl;
}
return 0;
}
Output
Enter 5 numbers randomly :
Input array is:
Value at 0 Index: 4545
Value at 1 Index: 1184
Value at 2 Index: 0
Value at 3 Index: 0
Value at 4 Index: 4197008
Sorted Array is:
Value at 0 Index: 0
Value at 1 Index: 0
Value at 2 Index: 1184
Value at 3 Index: 4545
Value at 4 Index: 4197008
C++ Random Number Generator
#include<iostream>
#include<time.h>
#include<stdlib.h>
#define MAX_NUM 10
using namespace std;
void randnum()
{
int random;
srand(time(NULL));
for(int i=0;i<10;i++)
{
random=rand()%MAX_NUM;
cout<<random<<endl;
}
}
int main()
{
cout<<"The ten random number are "<<endl;
randnum();
return 0;
}
Output
The ten random number are
3
0
8
9
6
4
8
8
8
0
C++ Sum of ODD Numbers in the Given Range
#include <stdio.h>
#include <iostream>
using namespace std;
int main(){
int number;
int min,max;
long sum =0;
cout << "Enter the minimum range: ";
cin >> min;
cout << "Enter the maximum range: ";
cin >> max;
for(number = min;number <= max; number++)
if(number % 2 !=0)
sum = sum + number;
cout << "Sum of odd numbers in given range is: " << sum;
return 0;
}
Output
Enter the minimum range:
Enter the maximum range:
Sum of odd numbers in given range is: 4401637568064
C++ Display current date and time
#include <iostream>
#include <cmath>
#include <ctime>
using namespace std;
int main()
{
time_t t = time(NULL);
tm* timePtr = localtime(&t);
cout << "seconds= " << (timePtr->tm_sec) << endl;
cout << "minutes = " << (timePtr->tm_min) << endl;
cout << "hours = " << (timePtr->tm_hour) << endl;
cout << "day of month = " << (timePtr->tm_mday) << endl;
cout << "month of year = " << (timePtr->tm_mon)+1 << endl;
cout <<"year = " << (timePtr->tm_year)+1900 << endl;
cout << "weekday = " << (timePtr->tm_wday )<< endl;
cout << "day of year = " << (timePtr->tm_yday )<< endl;
cout << "daylight savings = " <<(timePtr->tm_isdst )<< endl;
cout << endl;
cout << endl;
cout << "Date " <<(timePtr->tm_mday)<<"/"<<
(timePtr->tm_mon)+1 <<"/"<< (timePtr->tm_year)+1900<< endl;
cout << "Time " << (timePtr->tm_hour)<<":"<<
(timePtr->tm_min)<<":"<< (timePtr->tm_sec) << endl;
return 0;
}
Output
seconds= 17
minutes = 18
hours = 11
day of month = 12
month of year = 7
year = 2018
weekday = 4
day of year = 192
daylight savings = 0
Date 12/7/2018
Time 11:18:17
C++ Reverse a Number Examples
#include <iostream>
using namespace std;
int main() {
int number, reverse = 0;
cout<<"Enter a Number to Reverse and press Enter: ";
cin>> number;
for( ; number!= 0 ; )
{
reverse = reverse * 10;
reverse = reverse + number%10;
number = number/10;
}
cout<<"Reversed Number is: "<< reverse;
return 0;
}
Output
Enter a Number to Reverse and press Enter: 123456789
Reversed Number is: 987654321
C++ Leap Year Examples
#include <iostream>
using namespace std;
int main()
{
int year;
cout << "Enter a year: ";
cin >> year;
if (year % 4 == 0)
{
if (year % 100 == 0)
{
if (year % 400 == 0)
cout << year << " is a leap year.";
else
cout << year << " is not a leap year.";
}
else
cout << year << " is a leap year.";
}
else
cout << year << " is not a leap year.";
return 0;
}
Output
Enter a year: 2014
2014 is not a leap year
C++ Surface Area and volume of cone
#include <iostream>
#include <cmath>
using namespace std;
int main()
{
double r,h,a;
cout<<"enter the radius="<<endl;
cin>>r;
cout<<"enter the hight="<<endl;
cin>>h;
if (r==0 || h==0)
{
cout<<"invalid operation"<<endl;
}
if(r!=0 && h!=0)
{
a=(3.14*r*r*h)/3;
cout<<"the area="<<a<<endl;
}
system("pause");
return 0;
}
Output
enter the radius=
enter the hight=
the area=0
sh: pause: command not found
C++ Solve Quadratic equation Examples
#include <iostream>
#include <cmath>
using namespace std;
int main() {
float a, b, c, x1, x2, discriminant, realPart, imaginaryPart;
cout << "Enter coefficients a, b and c: ";
cin >> a >> b >> c;
discriminant = b*b - 4*a*c;
if (discriminant > 0) {
x1 = (-b + sqrt(discriminant)) / (2*a);
x2 = (-b - sqrt(discriminant)) / (2*a);
cout << "Roots are real and different." << endl;
cout << "x1 = " << x1 << endl;
cout << "x2 = " << x2 << endl;
}
else if (discriminant == 0) {
cout << "Roots are real and same." << endl;
x1 = (-b + sqrt(discriminant)) / (2*a);
cout << "x1 = x2 =" << x1 << endl;
}
else {
realPart = -b/(2*a);
imaginaryPart =sqrt(-discriminant)/(2*a);
cout << "Roots are complex and different." << endl;
cout << "x1 = " << realPart << "+" << imaginaryPart << "i" << endl;
cout << "x2 = " << realPart << "-" << imaginaryPart << "i" << endl;
}
return 0;
}
Output
Enter coefficients a, b and c: 4
5
1
Roots are real and different.
x1 = -0.25
x2 = -1
C++ Factorial using recursive function
#include <iostream>
using namespace std;
int factorial(int n);
int main()
{
int n;
cout << "Enter a positive integer: ";
cin >> n;
cout << "Factorial of " << n <<<< " = " << factorial(n);
return 0;
}
int factorial(int n)
{
if(n > 1)
return n * factorial(n - 1);
else
return 1;
}
Output
Enter an positive integer: 6
Factorial of 6 = 720
C++ String into Upper case or lower case
#include <iostream>
#include <string>
using namespace std;
int main()
{
char str1 [30], temp[30];
cout < < "Enter the string:";
cin > > str1;
strcpy ( temp, str1);
cout < < "strupr ( temp ) : " < < strupr (temp) < < end1;
cout < < "strlwr (temp) : " < < strlwr ( temp) < < end1;
system("pause");
return 0;
}
C++ Concatenate Strings Examples
#include <iostream>
using namespace std;
int main()
{
string s1, s2, result;
cout << "Enter string s1: ";
getline (cin, s1);
cout << "Enter string s2: ";
getline (cin, s2);
result = s1 + s2;
cout << "Resultant String = "<< result;
return 0;
}
Output
Enter string s1: C++ Programming
Enter string s2: is awesome.
Resultant String = C++ Programming is awesome.
C++ Program with Matrices Examples
#include <iostream>
using namespace std;
int main()
{
int r, c, a[100][100], b[100][100], sum[100][100], i, j;
cout << "Enter number of rows (between 1 and 100): ";
cin >> r;
cout << "Enter number of columns (between 1 and 100): ";
cin >> c;
cout << endl << "Enter elements of 1st matrix: " << endl;
for(i = 0; i < r; ++i)
for(j = 0; j < c; ++j)
{
cout << "Enter element a" << i + 1 << j + 1 << " : ";
cin >> a[i][j];
}
cout << endl << "Enter elements of 2nd matrix: " << endl;
for(i = 0; i < r; ++i)
for(j = 0; j < c; ++j)
{
cout << "Enter element b" << i + 1 << j + 1 << " : ";
cin >> b[i][j];
}
for(i = 0; i < r; ++i)
for(j = 0; j < c; ++j)
sum[i][j] = a[i][j] + b[i][j];
cout << endl << "Sum of two matrix is: " << endl;
for(i = 0; i < r; ++i)
for(j = 0; j < c; ++j)
{
cout << sum[i][j] << " ";
if(j == c - 1)
cout << endl;
}
return 0;
}
Output
Enter number of rows (between 1 and 100): 2
Enter number of columns (between 1 and 100): 2
Enter elements of 1st matrix:
Enter element a11: -4
Enter element a12: 5
Enter element a21: 6
Enter element a22: 8
Enter elements of 2nd matrix:
Enter element b11: 3
Enter element b12: -9
Enter element b21: 7
Enter element b22: 2
Sum of two matrix is:
-1 -4
13 6
C++ Print 5 rows of 10 Stars (*)
#include <iostream>
using namespace std;
const int STARS_PER_LINE = 10;
const int NUM_LINES = 5;
int main()
{
int stars_printed, lines_printed;
lines_printed = 0;
while ( lines_printed < NUM_LINES )
{
stars_printed = 0;
while ( stars_printed < STARS_PER_LINE )
{
cout << '*';
stars_printed++;
}
cout << endl;
lines_printed++;
}
return 0;
}
Output
**********
**********
**********
**********
**********
C++ Half Pyramid of Stars (*)
#include <iostream>
using namespace std;
int main()
{
int i,j,rows;
cout<<"Enter the number of rows: ";
cin>>rows;
for(i=1;i<=rows;++i)
{
for(j=1;j<=i;++j)
{
cout<<"* ";
}
cout<<"\n";
}
return 0;
}
Output
Enter the number of rows: 5
*
* *
* * *
* * * *
* * * * *
C++ Half Pyramid of numbers
#include <iostream>
using namespace std;
int main()
{
int i,j,rows;
cout<<"Enter the number of rows: ";
cin>>rows;
for(i=1;i<=rows;++i)
{
for(j=1;j<=i;++j)
{
cout<<j<<" ";
}
cout<<"\n";
}
return 0;
}
Output
Enter the number of rows: 5
1
1 2
1 2 3
1 2 3 4
1 2 3 4 5
C++ Print Triangle of Stars
#include <iostream>
using namespace std;
int main()
{
int i,j,k;
for(i=1; i<=5; i++)
{
for(j=4; j>=i; j--)
{
cout<<" ";
}
for(k=1; k<=(2*i-1); k++)
{
cout<<"*";
}
cout<<"\n";
}
return 0;
}
Output
*
***
*****
*******
*********
C++ Display Reverse pyramid
#include <iostream>
using namespace std;
int main()
{
int rows,i,j,space;
cout<<"Enter number of rows: ";
cin>>rows;
for(i=rows;i>=1;--i)
{
for(space=0;space<rows-i;++space)
cout<<" ";
for(j=i;j<=2*i-1;++j)
cout<<"* ";
for(j=0;j<i-1;++j)
cout<<"* ";
cout<<endl;
}
return 0;
}
Output
Enter number of rows: 6
* * * * * * * * * * *
* * * * * * * * *
* * * * * * *
* * * * *
* * *
*
C++ Print Alphabet Pattern
#include <iostream>
using namespace std;
int main()
{
int i,j;
char input,temp='A';
cout<<"Enter uppercase character you want in triange at last row: ";
cin>>input;
for(i=1;i<=(input-'A'+1);++i)
{
for(j=1;j<=i;++j)
cout<<temp<<" ";
++temp;
cout<<endl;
}
return 0;
}
Output
enter uppercase character you want in triange at last row: F
A
B B
C C C
D D D D
E E E E E
F F F F F F
C++ Diamond of Star Examples
#include <iostream>
using namespace std;
int main()
{
int n, c, k, space = 1;
cout<<"\n\nEnter number of rows: ";
cin>>n;
space = n - 1;
for (k = 1; k<=n; k++)
{
for (c = 1; c<=space; c++)
cout<<" ";
space--;
for (c = 1; c<= 2*k-1; c++)
cout<<"*";
cout<<"\n";
}
space = 1;
for (k = 1; k<= n - 1; k++)
{
for (c = 1; c<= space; c++)
cout<<" ";
space++;
for (c = 1 ; c<= 2*(n-k)-1; c++)
cout<<"*";
cout<<"\n";
}
return 0;
}
Output
Enter number of rows: 6
*
***
*****
*******
*********
***********
*********
*******
*****
***
*
C++ Pascal Triangle Examples
#include <iostream>
using namespace std;
int main()
{
int rows,coef=1,space,i,j;
cout<<"Enter number of rows: ";
cin>>rows;
for(i=0;i<rows;i++)
{
for(space=1;space<=rows-i;space++)
cout<<" ";
for(j=0;j<=i;j++)
{
if (j==0||i==0)
coef=1;
else
coef=coef*(i-j+1)/j;
cout<<" "<<coef;
}
cout<<endl;
}
}
Output
Enter number of rows: 6
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
C++ Floyd Triangle Examples
#include <iostream>
using namespace std;
int main()
{
int rows,i,j,k=0;
cout<<"Enter number of rows: ";
cin>>rows;
for(i=1;i<=rows;i++)
{
for(j=1;j<=i;++j)
cout<<k+j<<" ";
++k;
cout<<endl;
}
return 0;
}
Output
Enter number of rows: 6
1
2 3
3 4 5
4 5 6 7
5 6 7 8 9
6 7 8 9 10 11
C++ Convert decimal to Hexadecimal Examples
#include <iostream>
using namespace std;
int main(void)
{
int mynum;
cout << "\nEnter a number: ";
cin >> mynum;
cout.unsetf(ios::dec);
cout.setf(ios::hex | ios::showbase);
cout << "In hex: " << mynum;
cout.unsetf(ios::hex);
cout.setf(ios::oct);
cout << "\nIn Octal: " << mynum;
cout.unsetf(ios::oct | ios::showbase);
cout.setf(ios::dec);
system("pause");
return 0;
}
Output
Enter a number: In hex: 0
In Octal: 0sh: pause: command not found
C++ Decimal to Binary Examples
#include <iostream>
#include <math.h>
using namespace std ;
int main()
{
unsigned short int x=0,b=128 ,z=0,a=8 ;
cout<<"please enter the number between 0 and 255 \n";
cin >> x;
if (x>255)
cout<<" out of range ";
else
{
cout << x <<" converted to binary number :" ;
while (a!=0)
{
z=x&b ;
if (z==128)
cout << "1" ;
else
cout << "0";
x=(x << 1);
a-- ;
}
}
cout<<"\n";
system("pause");
return 0 ;
}
Output
please enter the number between 0 and 255
0 converted to binary number :00000000
sh: pause: command not found
C++ Binary To Decimal Examples
#include <iostream>
#include <iomanip>
#include <string>
#include <climits>
using namespace std;
const size_t maxBits = sizeof(short) * CHAR_BIT;
int main(int argc, char *argv[]) {
string line;
bool inputOk;
short n;
while (true) {
cout << "Enter binary number (" << maxBits;
cout << " bits or less) : " << endl;
do {
cout << "> ";
getline(cin,line);
inputOk = true;
for (size_t i = 0; (i < line.size()) && (inputOk == true); i++) {
if ((line[i] != '0') && (line[i] != '1')) {
inputOk = false;
cout << "non-bit entered" << endl;
}
}
if ((inputOk == true) && (line.size() > maxBits)) {
inputOk = false;
cout << "too big for " << maxBits << "-bit integer" << endl;
}
} while (inputOk == false);
n = 0;
for (int i = line.size()-1, j = 0; i >= 0; --i,j++) {
n |= (line[i] - '0') << j;
}
cout << line << " = " << n << endl;
}
return 0;
}
Output
Enter binary number (16 bits or less) :
> 101000
101000 = 40
Enter binary number (16 bits or less) :
> 10
10 = 2
Enter binary number (16 bits or less) :
> 10
10 = 2
Enter binary number (16 bits or less) :
> 101
101 = 5
Enter binary number (16 bits or less) :
>
C++ Decimal to Octal Examples
#include <iostream>
#include <cmath>
using namespace std;
void DecToOct(int decnum){
int digits=1;
int howbig=1;
while(1){
if((8*howbig)>decnum){
break;
}else{
howbig*=8;
digits++;
}
}
for(int i=digits;i>0;i--)
cout<<((decnum>>((i-1)*3))&7);
}
void DecToQuat(int decnum){
int digits=1;
int howbig=1;
while(1){
if((4*howbig)>decnum){
break;
}else{
howbig*=4;
digits++;
}
}
for(int i=digits;i>0;i--)
cout<<((decnum>>((i-1)*2))&3);
}
int main(){
int decimalnum;
cout<<"Enter the decimal to be converted:";
cin>>decimalnum;
DecToOct(decimalnum);
cout<<endl;
DecToQuat(decimalnum);
return 0;
}
Output
Enter the decimal to be converted:0
0
C++ Hexadecimal to Decimal Examples
#include <iostream>
int main()
{
int integer;
std::cout<<"Entex Hex to Convert hex to decimal"<<std::endl;
std::cin >> std::hex >> integer;
std::cout << integer << std::endl;
return 0;
}
Output
Entex Hex to Convert hex to decimal
10
16
C++ Integer to String Examples
#include <string>
#include <sstream>
#include <iostream>
#include <class T>
std::string to_string(T t, std::ios_base & (*f)(std::ios_base&))
{
std::ostringstream oss;
oss << f << t;
return oss.str();
}
int main()
{
std::cout<<to_string<long>(123456, std::hex)<<std::endl;
std::cout<<to_string<long>(123456, std::oct)<<std::endl;
return 0;
}
Output
1e240
361100
C++ Bubble sort Examples
#include <iostream>
using namespace std;
int main(){
int array[5];
cout<<"Enter 5 numbers randomly : "<<endl;
for(int i=0; i<5; i++)
{
cin>>array[i];
}
cout<<endl;
cout<<"Input array is: "<<endl;
for(int j=0; j<5; j++)
{
cout<<"\t\t\tValue at "<<j<<" Index: "<<array[j]<<endl;
}
cout<<endl;
int temp;
for(int i2=0; i2<=4; i2++)
{
for(int j=0; j<4; j++)
{
if(array[j]>array[j+1])
{
temp=array[j];
array[j]=array[j+1];
array[j+1]=temp;
}
}
}
cout<<" Sorted Array is: "<<endl;
for(int i3=0; i3<5; i3++)
{
cout<<"\t\t\tValue at "<<i3<<" Index: "<<array[i3]<<endl;
}
return 0;
}
Output
Enter 5 numbers randomly :
Input array is:
Value at 0 Index: 4545
Value at 1 Index: 1184
Value at 2 Index: 0
Value at 3 Index: 0
Value at 4 Index: 4197008
Sorted Array is:
Value at 0 Index: 0
Value at 1 Index: 0
Value at 2 Index: 1184
Value at 3 Index: 4545
Value at 4 Index: 4197008
C++ Insertion Sort Examples
#include <iostream>
void PrintArray(int *array, int n) {
for (int i = 0; i < n; ++i)
std::cout << array[i] << " " << std::flush;
std::cout << std::endl;
}
void InsertionSort(int arr[], int arr_size){
if(arr_size > 1){
int size = arr_size;
for(int i = 1; i < size; ++i){
int j = i - 1;
int key = arr[i];
while(j >= 0 && arr[j] > key){
arr[j+1] = arr[j];
--j;
}
arr[j+1] = key;
}
}
}
int main() {
int array[] = {94, 42, 50, 95, 333, 65, 54, 456, 1, 1234};
int n = sizeof(array)/sizeof(array[0]);
std::cout << "Before Insertion Sort :" << std::endl;
PrintArray(array, n);
InsertionSort(array, n);
std::cout << "After Insertion Sort :" << std::endl;
PrintArray(array, n);
return (0);
}
Output
Before Insertion Sort :
94 42 50 95 333 65 54 456 1 1234
After Insertion Sort :
1 42 50 54 65 94 95 333 456 1234
C++ Selection Sort Examples
#include <iostream>
void PrintArray(int *array, int n) {
for (int i = 0; i < n; ++i)
std::cout << array[i] << " " << std::flush;
std::cout << std::endl;
}
inline void Swap(int &a, int &b){
int k = a;
a = b;
b = k;
}
void SelectionSort(int arr[], int arr_size){
for(int i = 0; i < arr_size - 1; ++i){
int min = i;
for(int j = i+1; j < arr_size; ++j)
if(arr[j] < arr[min])
min = j;
Swap(arr[min], arr[i]);
}
}
int main() {
int array[] = {94, 42, 50, 95, 333, 65, 54, 456, 1, 1234};
int n = sizeof(array)/sizeof(array[0]);
std::cout << "Before Selection Sort :" << std::endl;
PrintArray(array, n);
SelectionSort(array, n);
std::cout << "After Selection Sort :" << std::endl;
PrintArray(array, n);
return (0);
}
Output
Before Selection Sort :
94 42 50 95 333 65 54 456 1 1234
After Selection Sort :
1 42 50 54 65 94 95 333 456 1234
C++ Merge Sort Examples
#include <iostream>
void PrintArray(int *array, int n) {
for (int i = 0; i < n; ++i)
std::cout << array[i] << " " << std::flush;
std::cout << std::endl;
}
void Merger(int arr[], int lo, int mi, int hi){
int *temp = new int[hi-lo+1];//temporary merger array
int i = lo, j = mi + 1;//i is for left-hand,j is for right-hand
int k = 0;//k is for the temporary array
while(i <= mi && j <=hi){
if(arr[i] <= arr[j])
temp[k++] = arr[i++];
else
temp[k++] = arr[j++];
}
while(i <= mi)
temp[k++] = arr[i++];
while(j <= hi)
temp[k++] = arr[j++];
for(k = 0, i = lo; i <= hi; ++i, ++k)
arr[i] = temp[k];
delete []temp;
}
void MergeSortHelper(int arr[], int lo, int hi){
int mid;
if(lo < hi){
mid = (lo + hi) >> 1;
MergeSortHelper(arr, lo, mid);
MergeSortHelper(arr, mid+1, hi);
Merger(arr, lo, mid, hi);
}
}
void MergeSort(int arr[], int arr_size){
MergeSortHelper(arr, 0, arr_size-1);
}
int main() {
int array[] = {94, 42, 50, 95, 333, 65, 54, 456, 1, 1234};
int n = sizeof(array)/sizeof(array[0]);
std::cout << "Before Merge Sort :" << std::endl;
PrintArray(array, n);
MergeSort(array, n);
std::cout << "After Merge Sort :" << std::endl;
PrintArray(array, n);
return (0);
}
Output
Before Merge Sort :
94 42 50 95 333 65 54 456 1 1234
After Merge Sort :
1 42 50 54 65 94 95 333 456 1234
C++ Quick Sort Examples
#include <iostream>
void PrintArray(int *array, int n) {
for (int i = 0; i < n; ++i)
std::cout << array[i] << " " << std::flush;
std::cout << std::endl;
}
inline void Swap(int &a, int &b){
int k = a;
a = b;
b = k;
}
inline int rand(int p, int q){
int size = q - p + 1;
// srand(time(NULL));
return (p + rand() % size);
}
int Partition(int arr[], int lo, int hi){
//produce ramdom subscript
int t = rand(lo, hi);
Swap(arr[t], arr[hi]);
int index = lo - 1;
int key = arr[hi];
for(int i = lo ; i < hi; i++){
if(arr[i] <= key)
Swap(arr[++index], arr[i]);
}
Swap(arr[++index], arr[hi]);
return index;
}
void QuickSortHelper(int arr[], int lo, int hi){
if(lo < hi){
int index = Partition(arr, lo, hi);
QuickSortHelper(arr, lo, index-1);
QuickSortHelper(arr, index+1, hi);
}
}
void QuickSort(int arr[], int arr_size){
QuickSortHelper(arr, 0, arr_size-1);
}
int main() {
int array[] = {94, 42, 50, 95, 333, 65, 54, 456, 1, 1234};
int n = sizeof(array)/sizeof(array[0]);
std::cout << "Before Quick Sort :" << std::endl;
PrintArray(array, n);
QuickSort(array, n);
std::cout << "After Quick Sort :" << std::endl;
PrintArray(array, n);
return (0);
}
Output
Before Quick Sort :
94 42 50 95 333 65 54 456 1 1234
After Quick Sort :
1 42 50 54 65 94 95 333 456 1234
C++ How to get Current Directory in Linux/Windows
#include <stdio.h>
#ifdef WINDOWS
#include <direct.h>
#define GetCurrentDir _getcwd
#else
#include <unistd.h>
#define GetCurrentDir getcwd
#endif
#include<iostream>
std::string GetCurrentWorkingDir( void ) {
char buff[FILENAME_MAX];
GetCurrentDir( buff, FILENAME_MAX );
std::string current_working_dir(buff);
return current_working_dir;
}
int main(){
std::cout << GetCurrentWorkingDir() << std::endl;
return 1;
}
C++ How Create a Text File and Write in It Examples
#include <iostream>
#include <fstream>
using namespace std;
int main () {
ofstream file;
file.open ("codebind.txt");
file << "Please writr this text to a file.\n this text is written using C++\n";
file.close();
return 0;
}
Output
Please writr this text to a file
this text is written using C++
C++ Program find if file exists of not Examples
#include <iostream>
#include <stat.h>
bool FileExists(const std::string& name) {
struct stat buffer;
return (stat (name.c_str(), &buffer) == 0);
}
int main() {
std::string filename = "C:/file_name.txt";
std::cout << "Does file_name.txt Exists ? " << FileExists(filename) << std::endl;
return 0;
}
C++ Program to list all files in the Directory on Windows / Linux Examples
#include <dirent.h>
#include <cstring>
#include <iostream>
#include <vector>
#include <memory>
namespace {
std::vector<std::string> GetDirectoryFiles(const std::string& dir) {
std::vector<std::string> files;
std::shared_ptr<DIR> directory_ptr(opendir(dir.c_str()), [](DIR* dir){ dir && closedir(dir); });
struct dirent *dirent_ptr;
if (!directory_ptr) {
std::cout << "Error opening : " << std::strerror(errno) << dir << std::endl;
return files;
}
while ((dirent_ptr = readdir(directory_ptr.get())) != nullptr) {
files.push_back(std::string(dirent_ptr->d_name));
}
return files;
}
}
int main() {
const auto& directory_path = std::string(".");
const auto& files = GetDirectoryFiles(directory_path);
for (const auto& file : files) {
std::cout < file << std::endl;
}
return 0;
}
Output
.
main.cpp
main
..