class Solution { public List<List<Integer>> threeSum(int[] nums){ List<List<Integer>> result = new ArrayList<List<Integer>>(); if(nums.length < 3){ return result; } Arrays.sort(nums); for(int i=0;i<nums.length && nums[i]<1;i++){ if(i>0 && nums[i] == nums[i-1]){ ...
(-1, -1, 2) » Solve this problem [Thoughts] Two-pointer scan. [Code] 1: vector<vector<int> >threeSum(vector<int> &num) {2: // Start typing your C/C++ solution below3: // DO NOT write intmain() function4: std::sort(num.begin(), num.end());5: vector<vector<int> > ...
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 classSolution { public: vector<vector<int>> threeSum(vector<int>& nums) { sort(nums.begin(), nums.end()); vector<vector<int> > validSet; for(...
链接:leetcode-cn.com/problem Link:leetcode.com/problems/3 双指针 O(N^2) 之前的Two Sum, 是有哈希和双指针两种解法的。 但是,对于本题,不能包含重复答案。对于这样的限制。排序更容易去重复, 需选择合适的代表, 所以采用双指针的方案 题目要求a + b + c = k, 只要遍历一遍数组,赋值给a,剩下的就...
这几天在做LeetCode 里面有2sum, 3sum(closest), 4sum等问题, 这类问题是典型的递归思路解题。该这类问题的关键在于,在进行求和求解前,要先排序Arrays.sort()可实现,而本文则着重探讨关于KSum问题。 leetcode求和问题描写叙述(K sum problem): K sum的求和问题通常是这样子描写叙述的:给你一组N个数字(比方...
1 class Solution { 2 public: 3 void dfs(int k,int n,int val,vector<int> tmp,vector<vector<int>>& result) 4 { 5 if(tmp.size()==k) 6 { 7 int sum=0; 8 for(int i=0;i<tmp.size();i++) 9 { 10 sum+=tmp[i]; 11 } 12 if(sum==n) result.push_back(tmp); 13 return...
还有求最接近target的2、3、4个数,是上述问题的变形,思路变化不大。 (二)leetcode求和问题描写叙述(K sum problem): K sum的求和问题通常是这样子描写叙述的:给你一组N个数字(比方 vector<int> num), 然后给你一个常数(比方 int target) ,我们的goal是在这一堆数里面找到K个数字。使得这K个数字的和等于...
代码(Python3) # arr[i] 的最大值 MAX_NUM: int = 100 # ans 需要取的模 MOD: int = 1_000_000_007 class Solution: def threeSumMulti(self, arr: List[int], target: int) -> int: # 统计 arr 中每个数字出现的次数 cnt: List[int] = [0] * (MAX_NUM + 1) for num in arr: cnt...
Problem:Given an arraySofnintegers, find three integers inSsuch that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactly one solution. For example, given array S = {-1 2 1 -4}, and target = 1. ...
3 45 3031 Typical recursion usage. classSolution { vector<vector<int>>ret;voiddfs(vector<int> curr,intcurrSum,intmaxN,intn,intk) {//Endingif(currSum ==n) {if(curr.size() ==k) { std::reverse(curr.begin(), curr.end());