fantow的博客

Find the Longest Substring Containing Vowels in Even Counts Given the string s, return the size of the longest substring containing each vowel an even number of times. That is, ‘a’, ‘e’, ‘i’, ‘o’, and...

Subarray Sum Equals K Given an array of integers and an integer k, you need to find the total number of continuous subarrays whose sum equals to k. 方法一:Presum 时间复杂度:O(n^2) 空间复杂度:O(n) public int su...