杨林峰的笔记

题目描述：描述有一个合法的字符串，合法是指左括号与右括号全部能配对，现在每次将这个序列第一个左括号删去，在将任意一个右括号删去，每次删去后的序列必须合法，求有多少种方法输入一个合法括号序列。输出方案数。样例输入()()()() (((())))()()样例输出1 24算法思想：这道题惯性思维是使用深度搜索，深度搜索函数有两个参数，输入字符串与标志位，其中标志位用于标志查询的是左括号还是右括号，如

题目链接：http://acm.nyist.net/JudgeOnline/problem.php?pid=1058描述给定整数a1、a2、…….an，判断是否可以从中选出若干数，使它们的和恰好为K。输入首先，n和k，n表示数的个数，k表示数的和。 接着一行n个数。 （1<=n<=20,保证不超int范围）输出如果和恰好可以为k，输出“YES”，并按输入顺序依次输出是由哪几个数的和组成，否则“N

题目链接：http://acm.nyist.net/JudgeOnline/problem.php?pid=635描述Shining Knight is the embodiment of justice and he has a very sharp sword can even cleavewall. Many bad guys are dead on his sword.One day, tw

题目链接：http://acm.nyist.net/JudgeOnline/problem.php?pid=491描述话说有这么一个图形，只有两种符号组成（‘+’或者‘-’），图形的最上层有n个符号，往下个数依次减一，形成倒置的金字塔形状，除第一层外（第一层为所有可能情况），每层形状都由上层决定，相邻的符号相同，则下层的符号为‘+’，反之，为‘-’;如下图所示（n = 3 时的两种情况)： 如

题目链接：http://acm.nyist.net/JudgeOnline/problem.php?pid=488描述有一个整数n，把从1到n的数字无重复的排列成环，且使每相邻两个数（包括首尾）的和都为素数，称为素数环。为了简便起见，我们规定每个素数环都从1开始。例如，下图就是6的一个素数环。 输入有多组测试数据，每组输入一个n(0<n<20)，n=0表示输入结束。输出每组第一行输出对应的Case

题目链接：http://acm.nyist.net/JudgeOnline/problem.php?pid=483描述Ignatius had a nightmare last night. He found himself in a labyrinth with a time bomb on him. The labyrinth has an exit, Ignatius should get o

题目链接：http://acm.nyist.net/JudgeOnline/problem.php?pid=284描述Many of us had played the game “Battle city” in our childhood, and some people (like me) even often play it on computer now. What we are dis

题目链接：https://leetcode.com/problems/word-search/description/描述Given a 2D board and a word, find if the word exists in the grid.The word can be constructed from letters of sequentially adjacent cell, whe

题目链接：http://acm.nyist.net/JudgeOnline/problem.php?pid=43描述There is a game which is called 24 Point game. In this game , you will be given some numbers. Your task is to find an expression which have al

题目链接：http://acm.nyist.net/JudgeOnline/problem.php?pid=42描述zyc从小就比较喜欢玩一些小游戏，其中就包括画一笔画，他想请你帮他写一个程序，判断一个图是否能够用一笔画下来。规定，所有的边都只能画一次，不能重复画。输入第一行只有一个正整数N(N≤10)表示测试数据的组数。 每组测试数据的第一行有两个正整数P,Q(P≤1000,Q≤2000)，分别

题目链接：http://acm.nyist.net/JudgeOnline/problem.php?pid=927描述One day,Tom’s girlfriend give him an array A which contains N integers and asked him:Can you choose some integers from the N integers and the