// 2200. Find All K-Distant Indices in an Array #include "leetcode.h" /* * you are given a 0-indexed integer array 'nums' and two integers 'key' and 'k' * a k-distant index is an index 'i' of 'nums' for which there exists at least * one index 'j' such that '|i - j| <= k' and 'nums[j] == key'. return a list of * all k-distant indices sorted in increasing order */ int *findKDistantIndices(int *nums, int numsSize, int key, int k, int *returnSize) { int *ans = (int *)calloc(numsSize, sizeof(int)); int ans_idx = 0, i = 0; while (i < numsSize) { if (nums[i] == key) { int prev_idx = !ans_idx ? -1 : ans[ans_idx - 1]; int start_idx = i - k > prev_idx ? i - k : prev_idx + 1; for (int j = start_idx; j <= i + k && j < numsSize; j++) ans[ans_idx++] = j; } i++; } *returnSize = ans_idx; return ans; } int main() { int n1[] = {3, 4, 9, 1, 3, 9, 5}, n2[] = {2, 2, 2, 2, 2}, rs1, rs2; int *fkdi1 = findKDistantIndices(n1, ARRAY_SIZE(n1), 9, 1, &rs1); int *fkdi2 = findKDistantIndices(n2, ARRAY_SIZE(n2), 2, 2, &rs2); for (int i = 0; i < rs1; i++) printf("%d ", fkdi1[i]); // expect: 1 2 3 4 5 6 printf("\n"); for (int i = 0; i < rs2; i++) printf("%d ", fkdi2[i]); // expect: 0 1 2 3 4 printf("\n"); free(fkdi1), free(fkdi2); }