维护前缀数组sums[],我们维护一个记录前缀和的map,map[x]表示前缀和是x距离当前i最近的下标。 那么状态转移方程就是dp[i] = max(dp[i-1], dp[map[sums[i]-target]]+1) class Solution { public:intdp[100005];intsum[100005];map<int,int> m;intmaxNonOverlappin
Return the maximum number of non-empty non-overlapping subarrays such that the sum of values in each subarray is equal to target. Example 1: Input: nums = [1,1,1,1,1], target = 2 Output: 2 Explanation: There are 2 non-overlapping subarrays [1,1,1,1,1] with sum equals to targ...
Solution 2. Prefix Sum with HashMap, O(N) runtime and space 1. Keep a running prefix sum and a hash map that stores the count of each different prefix sum value; Add (0, 1) to the hashmap, representing a sum of 0 for empty interval. 2. for a given prefix sum ps, check if ...
第一种是prefix sum + 双指针。 例如Minimum Size Subarray Sum - LeetCode: Given an array of n positive integers and a positive integers, find the minimal length of a contiguous subarray of which the sum ≥s. If there isn't one, return 0 instead. 用O(N)时间得到一个prefix sum array,可...
leetcode 209 长度最小的子数组 minimum-size-subarray-sum【ct】 思路:设置start和end都为数组第0个元素 , sum为数组的第一个元素,如果和>=target,就start++ ,sum-=nums[start] 否则end-- ,sum+=nums[end] 每次循环中去计算minLength,并返回 etc 数组 leetcode 560. Subarray Sum Equals K 动态规划DP...
2.Smallest Subarray with a given sum(easy) 2.1 问题描述 Given an array of positive integers nums and a positive integer target, return the minimal length of a 「contiguous subarray」 [numsl, numsl+1, ..., numsr-1, numsr] of which the sum is greater than or equal to target. If th...
public int minSubArrayLen(int target, int[] nums) { if (nums == null || nums.length == 0) return 0; int i = 0, j = 0, sum = 0, min = Integer.MAX_VALUE; while (i <= j && j < nums.length) { sum += nums[j]; ...
[LeetCode] Maximum Size Subarray Sum Equals k Problem 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 within the 32-bit signed integer ...
问最大最小时或许要维护单调队列/栈的单调性,由于其和target无直接关联性,很容易被忘记。 Given acircular integer arraynums of length n, returnthe maximum possible sum of a non-emptysubarrayofnums. Acircular arraymeans the end of the array connects to the beginning of the array. Formally, the ne...
这题跟560. subarray sum equals k几乎一毛一样。 我想到了用map和sum - k 来实现ONE PASS,但是不知道怎么维护一个类似560题里面那个count的值了。正确答案是用Math.max每次对比当前maxLen 和 i - map.get(sum-k)。 思维难度还是有的。 这题leetcode收费了。我贴一个别人的答案。注意这里的put始终是put...