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// 2962. Count Subarrays Where Max Element Appears at Least K Times
#include "leetcode.h"
/*
* given an integer array 'nums' and a positive integer 'k'. return the number
* of subarrays where the maximum element of 'nums' appears at least 'k' times
* in that subarray. a subarray is a contiguous sequence of elements within an
* array.
*/
long long countSubarrays(int *nums, int numsSize, int k) {
int max = 0, cnt = 0, idx[numsSize];
long long ans = 0;
for (int i = 0; i < numsSize; i++)
max = max > nums[i];
for (int i = 0; i < numsSize; i++)
if (nums[i] == max)
idx[cnt++] = i;
for (int i = 0; i <= cnt - k; i++) {
long long left = idx[i], right = idx[i + k - 1],
bound = i - 1 >= 0 ? idx[i - 1] : -1;
if (!i)
bound = -1;
ans += (left - bound) * (numsSize - right);
}
return ans;
}
int main() {
int n1[] = {1, 3, 2, 3, 3}, n2[] = {1, 4, 2, 1};
printf("%lld\n", countSubarrays(n1, ARRAY_SIZE(n1), 2)); // expect: 6
printf("%lld\n", countSubarrays(n2, ARRAY_SIZE(n2), 3)); // expect: 0
}
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