乘风破浪:LeetCode真题_040_Combination Sum II 一.前言 这次和上次的区别是元素不能重复使用了,这也简单,每一次去掉使用过的元素即可. 二.Combination Sum II 2.1 问题 2.2 分析与解决 通过分析我们可以知道使用递归就可以解决问题,并且这次我们从头遍历一次就不会出现多次使用某一个元素了. class Solution { List<List<Integer>> ans; public List<List<Intege…
You are given two linked lists representing two non-negative numbers. The most significant digit comes first and each of their nodes contain a single digit. Add the two numbers and return it as a linked list. You may assume the two numbers do not con…
Leetcode:面试题68 - II. 二叉树的最近公共祖先 Leetcode:面试题68 - II. 二叉树的最近公共祖先 Talk is cheap . Show me the code . /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), ri…
Leetcode:面试题55 - II. 平衡二叉树 Leetcode:面试题55 - II. 平衡二叉树 Talk is cheap . Show me the code . /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL)…
[LeetCode]Pascal's Triangle II 解题报告 标签(空格分隔): LeetCode 题目地址:https://leetcode.com/problems/pascals-triangle-ii/description/ 题目描述: Given an index k, return the kth row of the Pascal's triangle. For example, given k = 3, Return [1,3,3,1]. Note: Could yo…
[LeetCode]731. My Calendar II 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/my-calendar-ii/description/ 题目描述: Implement a MyCalendarTwo class to store your events. A new event can be added if…
[LeetCode]137. Single Number II 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/single-number-ii/description/ 题目描述: Given an array of integers, every element appears three times except for one, which appears exactly once. Find that singl…
[LeetCode]113. Path Sum II 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.me/ 题目地址:https://leetcode.com/problems/path-sum-ii/description/ 题目描述: Given a binary tree and a sum, find all root-to-leaf paths where each…
Basic Calculator II Implement a basic calculator to evaluate a simple expression string. The expression string contains only non-negative integers, +, -, *, / operators and empty spaces . The integer division should truncate toward zero. You may assu…
Basic Calculator Implement a basic calculator to evaluate a simple expression string. The expression string may contain open ( and closing parentheses ), the plus + or minus sign -, non-negative integers and empty spaces . You may assume that the giv…
Problem Statement Implement a basic calculator to evaluate a simple expression string. The expression string contains only non-negative integers, +, -, *, / operators and empty spaces . The integer division should truncate toward zero. Example 1: Inp…
一.Basic Calculator Total Accepted: 18480 Total Submissions: 94750 Difficulty: Medium Implement a basic calculator to evaluate a simple expression string. The expression string may contain open ( and closing parentheses ), the plus + or minus sign -, …
Problem: Implement a basic calculator to evaluate a simple expression string. The expression string contains only non-negative integers, +, -, *, / operators and empty spaces . The integer division should truncate toward zero. You may assume that the…
Basic Calculator Implement a basic calculator to evaluate a simple expression string. The expression string may contain open ( and closing parentheses ), the plus + or minus sign -, non-negative integers and empty spaces . You may assume that the giv…
Implement a basic calculator to evaluate a simple expression string. The expression string may contain open ( and closing parentheses ), the plus + or minus sign -, non-negative integers and empty spaces . You may assume that the given expression is…
Basic Calculator Implement a basic calculator to evaluate a simple expression string. The expression string may contain open ( and closing parentheses ), the plus + or minus sign -, non-negative integers and empty spaces ``. Example 1: Input: "1 + 1&…
作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 日期 题目地址:https://leetcode.com/problems/broken-calculator/ 题目描述 On a broken calculator that has a number showing on its display, we can perform two operations: Double: Multiply t…
On a broken calculator that has a number showing on its display, we can perform two operations: Double: Multiply the number on the display by 2, or; Decrement: Subtract 1 from the number on the display. Initially, the calculator is displaying the num…
题目如下: On a broken calculator that has a number showing on its display, we can perform two operations: Double: Multiply the number on the display by 2, or; Decrement: Subtract 1 from the number on the display. Initially, the calculator is displaying t…
Problem Link: http://oj.leetcode.com/problems/path-sum-ii/ The basic idea here is same to that of Path Sum. However, since the problem is asking for all possible root-to-leaf paths, so we should use BFS but not DFS. The python code is as follows. # D…
题目链接:Path Sum II | LeetCode OJ Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum. For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 1 return [ [5,4,11,2],…
LeetCode:Palindrome Partitioning 题目如下:(把一个字符串划分成几个回文子串,枚举所有可能的划分) Given a string s, partition s such that every substring of the partition is a palindrome. Return all possible palindrome partitioning of s. For example, given s = "aab",Return [ […
LeetCode:Pascal's Triangle Given numRows, generate the first numRows of Pascal's triangle. For example, given numRows = 5,Return [ [1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4,1] ] 分析:简单的模拟从第一层开始计算即可 class Solution { public: vector<vector<int> > g…
Given a linked list, return the node where the cycle begins. If there is no cycle, return null. Follow up: Can you solve it without using extra space? 解题思路,本题和上题十分类似,但是需要观察出一个规律,参考LeetCode:Linked List Cycle II JAVA实现如下: public ListNode detectCycle(Li…
https://leetcode.com/problems/h-index/ Given an array of citations (each citation is a non-negative integer) of a researcher, write a function to compute the researcher's h-index. According to the definition of h-index on Wikipedia: "A scientist has…
# -*- coding: utf8 -*-'''__author__ = 'dabay.wang@gmail.com' 45: Jump Game IIhttps://oj.leetcode.com/problems/jump-game-ii/ Given an array of non-negative integers, you are initially positioned at the first index of the array.Each element in the arra…
# -*- coding: utf8 -*-'''__author__ = 'dabay.wang@gmail.com' 40: Combination Sum IIhttps://oj.leetcode.com/problems/combination-sum-ii/ Given a collection of candidate numbers (C) and a target number (T),find all unique combinations in C where the ca…
