Leetcode 2962. Count Subarrays Where Max Element Appears at Least K Times

Espresso Macchiato2023-12-11 14:34

[Leetcode 2962. Count Subarrays Where Max Element Appears at Least K Times](#Leetcode 2962. Count Subarrays Where Max Element Appears at Least K Times)
- [1. 解题思路](#1. 解题思路)
- [2. 代码实现](#2. 代码实现)

题目链接：2962. Count Subarrays Where Max Element Appears at Least K Times

1. 解题思路

这一题思路上同样很直接，就是找到最大的元素所在的全部的位置坐标，然后分别考虑取 i i i到 i + k i+k i+k个最大元素时substring左右可以选择的起止点位置数目，相乘累加即可。

2. 代码实现

给出python代码实现如下：

python 复制代码

class Solution:
    def countSubarrays(self, nums: List[int], k: int) -> int:
        _max = max(nums)
        n = len(nums)
        flags = []
        for i, x in enumerate(nums):
            if x == _max:
                flags.append(i)
        m = len(flags)
        if m < k:
            return 0
        
        ans = 0
        flags.insert(0, -1)
        for i in range(m-k+1):
            ans += (flags[i+1]-flags[i]) * (n-flags[i+k])
        return ans

提交代码评测得到：耗时1040ms，占用内存30.7MB。