题目描述

题解思路

我们遍历长度为k的窗口，用一个哈希表记录窗口内的所有元素（用来对窗口内元素去重），我们取哈希表中元素数量等于k的窗口总和的最大值

题解代码

use std::collections::{HashMap};impl Solution {pub fn maximum_subarray_sum(nums: Vec<i32>, k: i32) -> i64 {let mut win = HashMap::new();let mut sum = 0;for i in 0..k as usize {win.insert(nums[i], i);sum += nums[i] as i64;}let mut ans = 0i64;if win.len() >= k as usize {ans = ans.max(sum);}for i in k as usize..nums.len() {if let Some(&start) = win.get(&nums[i-k as usize]) {if start == i - k as usize {win.remove(&nums[i-k as usize]);}}win.insert(nums[i], i);sum += (nums[i] - nums[i-k as usize]) as i64;if win.len() == k as usize {ans = ans.max(sum);}}ans}
}

题目链接

https://leetcode.cn/problems/maximum-sum-of-distinct-subarrays-with-length-k/description/