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// 2110. Number of Smooth Descent Periods of a Stock
#include "leetcode.h"
/*
* you are given an integer array 'prices' representing the daily price history
* of a stock where 'prices[i]' is the stock price on the i'th day. a smooth
* descent period of a stock consists of one or more contiguous days such that
* the price on each day is lower than the price on the peceding day by
* exactly 1. the first day of the period is exempted from this rule. return the
* number of smooth descent periods.
*/
long long getDescentPeriods(int *prices, int pricesSize) {
int *dp = (int *)malloc(pricesSize * sizeof(int));
dp[0] = 1;
long long ans = 1;
for (int i = 1; i < pricesSize; i++) {
dp[i] = prices[i] == prices[i - 1] - 1 ? dp[i - 1] + 1 : 1;
ans += dp[i];
}
free(dp);
return ans;
}
int main() {
int p1[] = {3, 2, 1, 4}, p2[] = {8, 6, 7, 7}, p3[] = {1};
printf("%lld\n", getDescentPeriods(p1, ARRAY_SIZE(p1))); // expect: 7
printf("%lld\n", getDescentPeriods(p2, ARRAY_SIZE(p2))); // expect: 4
printf("%lld\n", getDescentPeriods(p3, ARRAY_SIZE(p3))); // expect: 1
}
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