题目: Given two words (start and end), and a dictionary, find all shortest transformation sequence(s) from start to end, such that: Only one letter can be changed at a time Each intermediate word must exist in the dictionary For example, Given: start =…

考虑对于第$i$层$x$与第$i+1$层所对应的点$y$,点$p$在前$i$层中当且仅当$p$到$x$比$p$到$y$距离小 由此,考虑枚举第一层的一个点以及对应到第二层的边,通过bfs就可以确定第一层的点 接下来,标记第一层的点后,第一层的点剩下到未标记的点即为第二层的点,以此类推,就可以$o(m)$的确定所有点(注意还要判断) 注意到度数最小的点,必然出现在第一层或最后一层(否则第一层或最后一层对应的点度数少1),根据对称性,不难证明对于任意一个度数最少的点,存在一组方案满足其在第一层中 同…

#include<iostream> #include<queue> #include<cstring> using namespace std; int row,line,xx[4]={-1,1,0,0},yy[4]={0,0,-1,1}; char map[100][100]; bool vis[100][100]; struct node { int x,y,step; }st; void init() { int i,j; bool flag=1; for(i=…

在H * W的地图上有N个奶酪工厂,分别生产硬度为1-N的奶酪.有一只吃货老鼠准备从老鼠洞出发吃遍每一个工厂的奶酪.老鼠有一个体力值,初始时为1,每吃一个工厂的奶酪体力值增加1(每个工厂只能吃一次),且老鼠只能吃硬度不大于当前体力值的奶酪. 老鼠从当前格走到相邻的无障碍物的格(上下左右)需要时间1单位,有障碍物的格不能走.走到工厂上时即可吃到该工厂的奶酪,吃奶酪时间不计.问吃遍所有奶酪最少用时. 输入:第一行三个整数H(1 <= H <= 1000).W(1 <= W <=1000…

D. Phillip and Trains time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output The mobile application store has a new game called "Subway Roller". The protagonist of the game Philip is located…

1004 四子连棋   时间限制: 1 s   空间限制: 128000 KB   题目等级 : 黄金 Gold   题目描述 Description 在一个4*4的棋盘上摆放了14颗棋子,其中有7颗白色棋子,7颗黑色棋子,有两个空白地带,任何一颗黑白棋子都可以向上下左右四个方向移动到相邻的空格,这叫行棋一步,黑白双方交替走棋,任意一方可以先走,如果某个时刻使得任意一种颜色的棋子形成四个一线(包括斜线),这样的状态为目标棋局. ● ○ ●   ○ ● ○ ● ● ○ ● ○ ○ ● ○   输入…

Catch That Cow Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 77420   Accepted: 24457 Description Farmer John has been informed of the location of a fugitive cow and wants to catch her immediately. He starts at a point N (0 ≤ N ≤ 100,00…

Ideal Path Time Limit: 10000MS   Memory Limit: 65536K Total Submissions: 1754   Accepted: 240 Description New labyrinth attraction is open in New Lostland amusement park. The labyrinth consists of n rooms connected by m passages. Each passage is colo…

胜利大逃亡(续) Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 6070    Accepted Submission(s): 2096 Problem Description Ignatius再次被魔王抓走了(搞不懂他咋这么讨魔王喜欢)……这次魔王汲取了上次的教训,把Ignatius关在一个n*m的地牢里,并在地牢的某些地方安装了带…

Gap Time Limit: 20000/10000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 690    Accepted Submission(s): 380 Problem Description Let's play a card game called Gap.  You have 28 cards labeled with two-digit numbers…