Associate Software Engineer

// Simple C++ program to find the pair with sum closest to a given no.
#include 

using namespace std;

// Prints the pair with sum closest to x

void printClosest(int arr[], int n, int x)
{

int res_l, res_r; // To store indexes of result pair


// Initialize left and right indexes and difference between

// pair sum and x

int l = 0, r = n-1, diff = INT_MAX;


// While there are elements between l and r

while (r > l)

{

// Check if this pair is closer than the closest pair so far

if (abs(arr[l] + arr[r] - x) < diff)

{

res_l = l;

res_r = r;

diff = abs(arr[l] + arr[r] - x);

}


// If this pair has more sum, move to smaller values.

if (arr[l] + arr[r] > x)

r--;

else // Move to larger values

l++;

}


cout <<" The closest pair is " << arr[res_l] << " and " << arr[res_r];
}

// Driver program to test above functions

int main()
{

int arr[] = {10, 22, 28, 29, 30, 40}, x = 54;

int n = sizeof(arr)/sizeof(arr[0]);

printClosest(arr, n, x);

return 0;
}