zslomo的博客

题干: 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

Given an array S of n integers, find three integers in S such 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

题干： Given an array of integers, 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, whe

题干： Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d = target? Find all unique quadruplets in the array which gives the sum of target.Note: Elements in a

这里没有按照顺序更新，首先是因为做过了很多题，但是回头看看有些题解还是忘了，写博客是为了回顾，并且当初做题的时候有些题目自己不是很懂，网上找的要么乱七八糟要么是纯英文或者纯代码，看起来很费劲，所以想自己整理一下，也帮助后来者少走一些弯路 这道题是自己实现一个数据结构：trie，字典树，或者叫前缀树，很重要，并且在非中文的信息检索中应用广泛，但是大学期间却没有讲过，更不要提实现，而且可能很多同学跟我

题干： Given an array S of n integers, are there elements a, b, c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero.Note: Elements in a triplet (a,b,c) must

题目：Given a 2D board and a list of words from the dictionary, find all words in the board. Each word must be constructed from letters of sequentially adjacent cell, where “adjacent” cells are those hori

题目：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 with

题目：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 combinatio

题目The n-queens puzzle is the problem of placing n queens on an n×n chessboard such that no two queens attack each other.Given an integer n, return all distinct solutions to the n-queens puzzle.Each sol

题目上一篇我们使用了回溯法，然而提到回溯法就不得不提一个1848年提出的经典题目：8皇后问题，这个问题描述非常简单，一个8*8的棋盘上，放置8个皇后，使得每个皇后都不行相互攻击，既每个皇后的所在行、所在列、所在斜线上都不能有其他皇后，问有多少种解法，题目初看非常像图论问题，实际上也确实是，对图论感兴趣的同学可以去看离散数学的相关内容，这里我们用一种更巧妙也更直观的方法来解决这个问题，那就是——回溯法