小二终于开通博客了,真是高兴.最近在看Java,所以就拿leetcode练练手了.以后我会将自己解体过程中的思路写下来,分享给大家,其中有我自己原创的部分,也有参考别人的代码加入自己理解的部分,希望大家看了多提意见,一块加油. 问题描述: Given an array of integers, find two numbers such that they add up to a specific target number. The function twoSum should return…

题目描述: Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive. Example: Given nums = [-2, 0, 3, -5, 2, -1] sumRange(0, 2) -> 1 sumRange(2, 5) -> -1 sumRange(0, 5) -> -3 Note: You may assume that the ar…

题目描述: Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum. For example:Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ \ 7 2 1 retur…

题目描述: Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T. Each number in C may only be used once in the combination. Note: All numbers (including target) will b…

题目描述: Given a set of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T. The same repeated number may be chosen from C unlimited number of times. Note: All numbers (including target)…

题目描述: Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number. The function twoSum should return indices of the two numbers such that they add up to the target, where in…

Find all possible combinations of k numbers that add up to a number n, given that only numbers from 1 to 9 can be used and each combination should be a unique set of numbers. Ensure that numbers within the set are sorted in ascending order. Example 1…

LeetCode one Two Sum (JAVA) 简介:给定一个数组和目标值,寻找数组中符合求和条件的两个数. 问题详解: 给定一个数据类型为int的数组,一个数据类型为int的目标值target,要求是在数组中寻求两个数字,使得两个数求和的值等于给定的target,要求以数组返回符合条件的索引. 技巧:可以假设数组中没有重复元素,因为我们只返回一个符合条件的数组,所以数组中只需要一个符合要求的数字就可以了. 举例: 给定数组 nums={5,8,7,2,11},target= 10, 因…

Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solution, and you may not use the same element twice. Example: Given nums = [2, 7, 11, 15]…

Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sums to target. Each number in candidates may only be used once in the combination. Note: All nu…

Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum. For example:Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ \ 7 2 1 return true…

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], [5,8,4,5] ] 112. Path Sum 的拓展,上一…

Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number. The function twoSum should return indices of the two numbers such that they add up to the target, where index1 m…

Design and implement a TwoSum class. It should support the following operations:add and find. add - Add the number to an internal data structure.find - Find if there exists any pair of numbers which sum is equal to the value. For example,add(1); add(…

Find all possible combinations of k numbers that add up to a number n, given that only numbers from 1 to 9 can be used and each combination should be a unique set of numbers. Example 1: Input: k = 3, n = 7 Output: [[1,2,4]] Example 2: Input: k = 3, n…

Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive. Example: Given nums = [-2, 0, 3, -5, 2, -1] sumRange(0, 2) -> 1 sumRange(2, 5) -> -1 sumRange(0, 5) -> -3 Note: You may assume that the array do…

Given a 2D matrix matrix, find the sum of the elements inside the rectangle defined by its upper left corner (row1, col1) and lower right corner (row2, col2). The above rectangle (with the red border) is defined by (row1, col1) = (2, 1) and (row2, co…

Given an integer array with all positive numbers and no duplicates, find the number of possible combinations that add up to a positive integer target. Example: nums = [1, 2, 3] target = 4 The possible combination ways are: (1, 1, 1, 1) (1, 1, 2) (1,…

Given a Binary Search Tree and a target number, return true if there exist two elements in the BST such that their sum is equal to the given target. Example 1: Input: 5 / \ 3 6 / \ \ 2 4 7 Target = 9 Output: TrueExample 2: Input: 5 / \ 3 6 / \ \ 2 4…

LeetCode 1 Two Sum 解题报告 偶然间听见leetcode这个平台,这里面题量也不是很多200多题,打算平时有空在研究生期间就刷完,跟跟多的练习算法的人进行交流思想,一定的ACM算法积累可以对以后在对算法中优化带来好处.Ok,今天是我做的第一题Add Two Sum. 题目要求 Given an array of integers, find two numbers such that they add up to a specific target number. The fu…

题目: Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number. The function twoSum should return indices of the two numbers such that they add up to the target, where inde…

一. 题目 1. Two Sum II Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number. The function twoSum should return indices of the two numbers such that they add up to the ta…

一. 题目 1. Two SumTotal Accepted: 241484 Total Submissions: 1005339 Difficulty: Easy Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solutio…

leetcode - 40. Combination Sum II - Medium descrition Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T. Each number in C may only be used once in the combinat…

leetcode - 39. Combination Sum - Medium descrition Given a set of candidate numbers (C) (without duplicates) and a target number (T), find all unique combinations in C where the candidate numbers sums to T. The same repeated number may be chosen from…

Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sums to target. Each number in candidates may only be used once in the combination. Note: All nu…

You are given a binary tree in which each node contains an integer value. Find the number of paths that sum to a given value. The path does not need to start or end at the root or a leaf, but it must go downwards (traveling only from parent nodes to…

You are given a binary tree in which each node contains an integer value. Find the number of paths that sum to a given value. The path does not need to start or end at the root or a leaf, but it must go downwards (traveling only from parent nodes to…

If the depth of a tree is smaller than 5, then this tree can be represented by a list of three-digits integers. For each integer in this list: The hundreds digit represents the depth D of this node, 1 <= D <= 4. The tens digit represents the positio…

[LeetCode]129. Sum Root to Leaf Numbers 解题报告(Python) 标签(空格分隔): LeetCode 题目地址:https://leetcode.com/problems/sum-root-to-leaf-numbers/description/ 题目描述: Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a numbe…