Question

Write a C++ program to find the number of pairs of integers in a given array of integers whose sum is equal to a specified number.

Answer 1

CODE :

#include <iostream>
using namespace std;

int main()
{
  
int a[1000], n;
cout << "Please enter the no of elements in an array : \n";
cin >> n; // read n no elements in an array
cout << "please enter the array of elements : \n";

for (int i=0; i < n; i++)
{
cin >> a[i]; // read elements into an arrray
}
  
int sum = 0;
  
cout << "please enter the sum : \n";
cin >> sum; // read the sum to print the pairs
  
int i, count = 0;
  
cout <<"Array pairs whose sum equal to " <<sum <<" is: \n";
  
  
  
for (int i = 0; i < n; i++)
{
for (int j = i + 1; j < n; j++)
{
if (a[i] + a[j] == sum)
{
cout << "\n" << a[i] << "," << a[j]; // printing pairs that are equal to the sum
count++;
}
}
}

cout <<"\nThe no of Array pairs whose sum equal to " <<sum <<" is: \n";
cout << count; // printing no of pairs that are equal to the sum
  
return 0;
}

OUTPUT :