#include <iostream>
int countPairsWithSpecificDifference(int arr[], int size, int difference) {
int count = 0;
for (int i = 0; i < size; i++) {
for (int j = i + 1; j < size; j++) {
if (arr[i] - arr[j] == difference || arr[j] - arr[i] == difference) {
count++;
}
}
}
return count;
}
int main()
{
int arr[] = {25, 16, 8, 12, 20, 17, 0, 4, 21, 26};
int difference = 4;
// 7 pairs with difference 4: {25, 21}, {16, 12}, {16, 20}, {8, 12}, {8, 4}, {17, 21} {0, 4}
int size = sizeof(arr)/sizeof(arr[0]);
std::cout << countPairsWithSpecificDifference(arr, size, difference);
return 0;
}
/*
run:
7
*/