#include <iostream>
#include <unordered_map>
using namespace std;
// Function to find a pair in an array with a given sum using hashing
void findPair(int nums[], int n, int target)
{
// create an empty map
unordered_map<int, int> map;
// do for each element
for (int i = 0; i < n; i++)
{
// check if pair (nums[i], target - nums[i]) exists
// if the difference is seen before, print the pair
if (map.find(target - nums[i]) != map.end())
{
cout << "Pair found (" << nums[map[target - nums[i]]] << ", "
<< nums[i] << ")
";
return;
}
// store index of the current element in the map
map[nums[i]] = i;
}
// we reach here if the pair is not found
cout << "Pair not found";
}
int main()
{
int nums[] = { 8, 7, 2, 5, 3, 1 };
int target = 10;
int n = sizeof(nums)/sizeof(nums[0]);
findPair(nums, n, target);
return 0;
}