在遍历到位置 i 时,假设当前的前缀和是 psum,那么 hashmap[psum-k] 即为以当前位置结尾、满足条件的区间个数。 classSolution(object):defsubarraySum(self,nums,k):""":type nums: List[int]:type k: int:rtype: int"""count=0psum=0hash_map={}hash_map[0]=1foriinnums:psum+=icount+=hash...
树中距离之和 Sum of Distances in Tree 132 -- 10:09 App LeetCode力扣 493. 翻转对 Reverse Pairs 136 -- 7:44 App LeetCode力扣 56. 合并区间 Merge Intervals 389 -- 11:26 App Python每日一练-字典数组练习-歌唱比赛名次 156 -- 7:23 App LeetCode力扣 118. 杨辉三角 Pascal's Triangle...
扫描的时候,如果 map 存在 sum(下图黄色部分) 和 sum - k(下图红色部分),就说明有满足条件的子数组,因为他们的差值是 k。同时因为数组可能存在负数的关系,加入前缀和的时候需要判断 key 是否存在过。举个例子,比如前 N 项的和是 sum,前 N-1 项的和是 sum - k,那么前 N 项的和 - 前 N-1 项的和 ...
所以我们简历Map存储累计和sum出现的次数,如果sum-k存在于map中,则累加和为k的子数组一定存在。 publicintsubarraySum(int[] nums,intk){ HashMap<Integer, Integer> map =newHashMap<>(); map.put(0,1);//初始加入0,例如nums【0】=10,k=10,如果0不在map中就少一个resintres=0;intcur=0;for(inti=...
leetcode974. Subarray Sums Divisible by K Given an array A of integers, return the number of (contiguous, non-empty) subarrays that have a sum divisible by K. Example 1: Note: 给定一个集合,求这个集合中子集的个数,其中对子集的要求是子集中元素的和能被k整除。 记数组pre[i+1]表示前 i...
第一个例子是Leetcode 325 Maximum Size Subarray Sum Equals k. 付费题我完整复制一下题目。 Given an array nums and a target value k, find the maximum length of a subarray that sums to k. If there isn't one, return 0 instead. Note:The sum of the entire nums array is guaranteed to fit...
560. Subarray Sum Equals K 标签(空格分隔): leetcode array medium 题目 Given an array of integers and an integerk, you need to find the total number of continuous subarrays whose sum equals tok. Example 1: Input:nums = [1,1,1], k = 2Output:2 ...
LeetCode Top 100 Liked Questions 560. Subarray Sum Equals K (Java版; Medium) 题目描述 AI检测代码解析 Given an array of integers and an integer k, you need to find the total number of continuous subarrays whose sum equals to k.
[Leetcode] 560. Subarray Sum Equals K Problem: https://leetcode.com/problems/subarray-sum-equals-k/ Solution1: 利用累计和 Time complexity: O(n2) Space complexity: O(n) Solution2: 移动subarray的起点和终点,计算两点之间的和 Time complexity: O(n2) Space complexit......
classSolution {public:intmaxSubArrayLen(vector<int>& nums,intk) {if(nums.empty())return0;intres =0; unordered_map<int, vector<int>>m; m[nums[0]].push_back(0); vector<int> sum =nums;for(inti =1; i < nums.size(); ++i) { ...