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// 795. Number of Subarrays with Bounded Maximum
#include "leetcode.h"
/*
* given an integer array 'nums' and two integers 'left' and 'right', return the
* number of contiguous non empty subarrays such that the value of the maximum
* array element in that subarray is in the range '[left, right]'. the test
* cases are generated such that the answer will fit into a 32 bit integer.
*/
int helper(int *nums, int n, int left) {
if (!n)
return 0;
long long res = (long long)(n + 1) * n / 2;
int cnt = 0;
for (int i = 0; i < n; i++) {
if (nums[i] < left)
cnt++;
else {
res -= (cnt + 1) * cnt / 2;
cnt = 0;
}
}
res -= (cnt + 1) * cnt / 2;
return res;
}
int numSubarrayBoundedMax(int *nums, int numsSize, int left, int right) {
int ans = 0, prev = 0;
for (int i = 0; i < numsSize; i++)
if (nums[i] > right) {
ans += helper(&nums[prev], i - prev, left);
prev = i + 1;
}
ans += helper(&nums[prev], numsSize - prev, left);
return ans;
}
int main() {
int n1[] = {2, 1, 4, 3}, n2[] = {2, 9, 2, 5, 6};
printf("%d\n", numSubarrayBoundedMax(n1, ARRAY_SIZE(n1), 2, 3)); // expect: 3
printf("%d\n", numSubarrayBoundedMax(n2, ARRAY_SIZE(n2), 2, 8)); // expect: 7
}
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