// 2176. Count Equal and Divisible Pairs in an Array #include "leetcode.h" /* * given a 0-indexed integer array 'nums' of length 'n' and an integer 'k', * return the number of pairs '(i, j)' where '0 <= i < j < n' such that 'nums[i] * == nums[j]' and '(i * j)' is divisble by 'k'. */ int countPairs(int *nums, int numsSize, int k) { int cnt = 0; for (int i = 0; i < numsSize; i++) for (int j = i + 1; j < numsSize; j++) if (nums[i] == nums[j] && !((i * j) % k)) cnt++; return cnt; } int main() { int n1[] = {3, 1, 2, 2, 2, 1, 3}, n2[] = {1, 2, 3, 4}; printf("%d\n", countPairs(n1, ARRAY_SIZE(n1), 2)); // expect: 4 printf("%d\n", countPairs(n2, ARRAY_SIZE(n2), 1)); // expect: 0 }