Find Pair Given Difference- 17 May - The Logic Tutorial

Given an array arr[] of size n and an integer x, return 1 if there exists a pair of elements in the array whose absolute difference is x, otherwise, return -1.

Example 1:

Input:

n = 6

x = 78

arr[] = {5, 20, 3, 2, 5, 80}

Output:

1

Explanation:

Pair (2, 80) have absolute difference of 78.

Example 2:

Input:

n = 5

x = 45

arr[] = {90, 70, 20, 80, 50}

Output:

-1

Explanation:

There is no pair with absolute difference of 45.

HTML

class Solution {
public:
    int findPair(int n, int x, vector<int> &arr) {
        // Step 1: Sort the array
        sort(arr.begin(), arr.end());
        // Step 2: Initialize two pointers
        int i = 0, j = 1;
        // Step 3: Use a while loop to find the pair with the given difference
        while (i < n && j < n) {
            // Calculate the difference between the current pair of elements
            int diff = abs(arr[j] - arr[i]);
            // Step 4: Check if the difference equals the target value x
            if (diff == x && i != j) {
                // If we find such a pair, return 1
                return 1;
            } else if (diff < x) {
                // If the difference is less than x, move the second pointer to the right
                j++;
            } else {
                // If the difference is greater than x, move the first pointer to the right
                i++;
            }
            // Step 5: Ensure i and j do not overlap incorrectly
            if (i == j) {
                j++;
            }
        }
        // Step 6: If no such pair is found, return -1
        return -1;
    }
};