Given an array of unique integers, return a pair of integers that sum up to a target sum.

Basic method to find a pair whose sum matches with given sum:

C program:

#include <iostream>
#include <algorithm>
 // Function to find a pair  using Sorting in an array with given sum
void findPair(int arr[], int n, int sum){
     std::sort(arr, arr + n);   // sort the array in ascending order
    int i = 0;
    int j = n - 1;
     while (i < j) {   // loop till i is less than j
        if (arr[i] + arr[j] == sum){  // sum found
       std::cout << "Pair found"<<”\n”<< arr[i]<<arr[j];
       return;}
       // decrement j if total is more than the sum
         // increment i  if total is less than the sum
      (arr[i] + arr[j] < sum)? i++: j--;}
    // No pair exists in an array with the desired sum
    std::cout << "Pair not found";}
// Main function from which find pair function is called
int main()
{ int arr[] = { 8, 7, 2, 5, 3, 1};
 int sum = 10;
 int n = sizeof(arr)/sizeof(arr[0]);
 findPair(arr, n, sum);
return 0;}