题意:给出一个矩形,问有多少块连通的W 当找到W的时候,进行广搜,然后将搜过的W变成点,直到不能再搜,进行下一次广搜,最后搜的次数即为水塘的个数 看的PPT里面讲的是种子填充法. 种子填充算法: 从多边形区域的一个内点开始,由内向外用给定的颜色画点直到边界为止.如果边界是以一种颜色指定的,则种子填充算法可逐个像素地处理直到遇到边界颜色为止 对于这一题: 先枚举矩阵中的每一个元素,当元素为W的时候,对它进行种子填充(BFS) 种子填充过程: 1)将八个方向的状态分别加进队列 2)如果元素为W,将其…

Lake Counting Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 48370 Accepted: 23775 Description Due to recent rains, water has pooled in various places in Farmer John's field, which is represented by a rectangle of N x M (1 <= N <= 100; 1…

Lake Counting Time Limit: 1000MS     Memory Limit: 65536K Total Submissions: 17917     Accepted: 9069 Description Due to recent rains, water has pooled in various places in Farmer John's field, which is represented by a rectangle of N x M (1 <= N <=…

Lake Counting Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 28966   Accepted: 14505 Description Due to recent rains, water has pooled in various places in Farmer John's field, which is represented by a rectangle of N x M (1 <= N <= 10…

Lake Counting Description Due to recent rains, water has pooled in various places in Farmer John's field, which is represented by a rectangle of N x M (1 <= N <= 100; 1 <= M <= 100) squares. Each square contains either water ('W') or dry land…

Lake Counting Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 40370   Accepted: 20015 Description Due to recent rains, water has pooled in various places in Farmer John's field, which is represented by a rectangle of N x M (1 <= N <= 10…

Lake Counting Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 18201   Accepted: 9192 Description Due to recent rains, water has pooled in various places in Farmer John's field, which is represented by a rectangle of N x M (1 <= N <= 100…

Lake Counting Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 20782   Accepted: 10473 Description Due to recent rains, water has pooled in various places in Farmer John's field, which is represented by a rectangle of N x M (1 <= N <= 10…

Lake Counting Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 53301   Accepted: 26062 Description Due to recent rains, water has pooled in various places in Farmer John's field, which is represented by a rectangle of N x M (1 <= N <= 10…

POJ 3669 去看流星雨,不料流星掉下来会砸毁上下左右中五个点.每个流星掉下的位置和时间都不同,求能否活命,如果能活命,最短的逃跑时间是多少? 思路:对流星雨排序,然后将地图的每个点的值设为该点最早被炸毁的时间 #include <iostream> #include <algorithm> #include <queue> #include <cstring> using namespace std; #define INDEX_MAX 512 int…

http://poj.org/problem?id=2386 http://acm.hdu.edu.cn/showproblem.php?pid=1241 求有多少个连通子图.复杂度都是O(n*m). #include <cstdio> ][]; int n,m; void dfs(int x,int y) { ;i<=;i++) ;j<=;j++) //循环遍历8个方向 { int xx=x+i,yy=y+j; &&xx<n&&yy>=…

题目地址:http://poj.org/problem?id=3126 Input One line with a positive number: the number of test cases (at most 100). Then for each test case, one line with two numbers separated by a blank. Both numbers are four-digit primes (without leading zeros). Ou…

题目链接 http://poj.org/problem?id=2251 题意 给出一个三维地图 给出一个起点 和 一个终点 '#' 表示 墙 走不通 '.' 表示 路 可以走通 求 从起点到终点的 最短路径 走不通输出 Trapped! 方向 是可以 上,下,东南西北 六个方向 思路 BFS板子题 注意要记录 S 和 E 的位置 因为不一定是固定的 要标记访问 AC代码 #include <cstdio> #include <cstring> #include <ctype.…

题目链接 http://poj.org/problem?id=3984 思路 因为要找最短路 用BFS 而且 每一次 往下一层搜 要记录当前状态 之前走的步的坐标 最后 找到最短路后 输出坐标就可以了 AC代码 #include <cstdio> #include <cstring> #include <ctype.h> #include <cstdlib> #include <cmath> #include <climits> #i…

http://poj.org/problem?id=2386 题目大意: 有一个大小为N*M的园子,雨后积起了水.八连通的积水被认为是连接在一起的.请求出院子里共有多少水洼? 思路: 水题~直接DFS,DFS过程把途中表示水洼的W改为'.',看DFS了几次即可. #include<cstdio> #include<cstring> const int MAXN=100+10; char map[MAXN][MAXN]; int n,m; void dfs(int x,int y)…

链接:http://poj.org/problem?id=2386 题解 #include<cstdio> #include<stack> using namespace std; ,MAX_N=; char a[MAX_N][MAX_M]; int N,M; //现在位置 (x,y) void dfs(int x,int y){ a[x][y]='.'; //将现在所在位置替换为'.',即旱地 ;dx<=;dx++){ //循环遍历连通的8个方向:上.下.左.右.左上.左下…

地址 http://poj.org/problem?id=2386 <挑战程序设计竞赛>习题 题目描述Description Due to recent rains, water has pooled in various places in Farmer John’s field, which is represented by a rectangle of N x M (1 <= N <= 100; 1 <= M <= 100) squares. Each squa…

<题目链接> 题目大意: 给你两个四位数,它们均为素数,以第一个四位数作为起点,每次能够变换该四位数的任意一位,变换后的四位数也必须是素数,问你是否能够通过变换使得第一个四位数变成第二个四位数. 解题分析: 先打一张素数表,然后进行BFS搜索,对于每次搜索的当前数,枚举某一位与它不同的所有数,判断它是否符合条件,如果符合,就将它加入队列,继续搜索. #include<stdio.h> #include<string.h> #include<iostream>…

题意:给出一个三维坐标的牢,给出起点st,给出终点en,问能够在多少秒内逃出. 学习的第一题三维的广搜@_@ 过程和二维的一样,只是搜索方向可以有6个方向(x,y,z的正半轴,负半轴) 另外这一题的输入的方式还要再多看看--@_@-- #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<queue> #define maxn 55 u…

题意:给定一个n*m的矩阵,让你判断有多少个连通块. 析:用DFS搜一下即可. 代码如下: #pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #include <string> #include <cstdlib> #include <cmath> #include <iostream> #include <cstring&…

题目大意:有N*M的矩阵稻田,'W'表示有积水的地方, '.'表示是干旱的地方,问稻田内一共有多少块积水,根据样例很容易得出,积水是8个方向任一方向相连即可. 题目大意:有N*M的矩阵稻田,'W'表示有积水的地方, '.'表示是干旱的地方,问稻田内一共有多少块积水,根据样例很容易得出,积水是8个方向任一方向相连即可.  题目大意:有N*M的矩阵稻田,'W'表示有积水的地方, '.'表示是干旱的地方,问稻田内一共有多少块积水,根据样例很容易得出,积水是8个方向任一方向相连即可.  题目大意:有N*…

Description Due to recent rains, water has pooled in various places in Farmer John's field, which is represented by a rectangle of N x M (1 <= N <= 100; 1 <= M <= 100) squares. Each square contains either water ('W') or dry land ('.'). Farmer…

简单的深度搜索就能够了,看见有人说什么使用并查集,那简直是大算法小用了. 由于能够深搜而不用回溯.故此效率就是O(N*M)了. 技巧就是添加一个标志P,每次搜索到池塘,即有W字母,那么就觉得搜索到一个池塘了,P值为真. 搜索过的池塘不要反复搜索,故此,每次走过的池塘都改成其它字母.如'@',或者'#',随便一个都能够. 然后8个方向搜索. #include <stdio.h> #include <vector> #include <string.h> #include…

Description Due to recent rains, water has pooled in various places in Farmer John's field, which is represented by a rectangle of N x M (1 <= N <= 100; 1 <= M <= 100) squares. Each square contains either water ('W') or dry land ('.'). Farmer…

迷宫问题 Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 31428 Accepted: 18000 Description 定义一个二维数组: int maze[5][5] = { 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, }; 它表示一个迷宫,其中的1表示墙壁,0表示可以走的路,只能横着走或竖着走,不能斜着走,要求编…

http://blog.csdn.net/c20182030/article/details/52327948 1388:Lake Counting 总时间限制:   1000ms   内存限制:   65536kB 描述 Due to recent rains, water has pooled in various places in Farmer John's field, which is represented by a rectangle of N x M (1 <= N <= 1…

Lake Counting Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 20003   Accepted: 10063 Description Due to recent rains, water has pooled in various places in Farmer John's field, which is represented by a rectangle of N x M (1 <= N <= 10…

http://poj.org/problem?id=3278 Catch That Cow Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 52463   Accepted: 16451 Description Farmer John has been informed of the location of a fugitive cow and wants to catch her immediately. He star…

POJ图论分类[转] 一个很不错的图论分类,非常感谢原版的作者!!!在这里分享给大家,爱好图论的ACMer不寂寞了... (很抱歉没有找到此题集整理的原创作者,感谢知情的朋友给个原创链接) POJ:http://poj.org/ 1062* 昂贵的聘礼 枚举等级限制+dijkstra 1087* A Plug for UNIX 2分匹配 1094 Sorting It All Out floyd 或 拓扑 1112* Team Them Up! 2分图染色+DP 1125 Stockbroker…

[题目] 农夫知道一头牛的位置,想要抓住它.农夫和牛都位于数轴上,农夫起始位于点N(0≤N≤100000),牛位于点K(0≤K≤100000).农夫有两种移动方式: 1.从X移动到X-1或X+1,每次移动花费一分钟 2.从X移动到2*X,每次移动花费一分钟 假设牛没有意识到农夫的行动,站在原地不动.农夫最少要花多少时间才能抓住牛? [输入] 两个整数,N和K. [输出] 一个整数,农夫抓到牛所要花费的最小分钟数. [输入样例] 5 17 [输出样例] 4 [思路]就是简单的bfs,但是我忘记了上…