Description The farm has many hills upon which Farmer John would like to place guards to ensure the safety of his valuable milk-cows. He wonders how many guards he will need if he wishes to put one on top of each hill. He has a map supplied as a matr…

题目 1619: [Usaco2008 Nov]Guarding the Farm 保卫牧场 Time Limit: 5 Sec  Memory Limit: 64 MB Submit: 491  Solved: 218 [Submit][Status] Description The farm has many hills upon which Farmer John would like to place guards to ensure the safety of his valuable…

1619: [Usaco2008 Nov]Guarding the Farm 保卫牧场 Time Limit: 5 Sec  Memory Limit: 64 MBSubmit: 498  Solved: 223[Submit][Status] Description The farm has many hills upon which Farmer John would like to place guards to ensure the safety of his valuable milk…

Description The farm has many hills upon which Farmer John would like to place guards to ensure the safety of his valuable milk-cows. He wonders how many guards he will need if he wishes to put one on top of each hill. He has a map supplied as a matr…

http://www.lydsy.com/JudgeOnline/problem.php?id=1619 首先不得不说,,题目没看懂.... 原来就是找一个下降的联通块.... 排序后dfs标记即可.. #include <cstdio> #include <cstring> #include <cmath> #include <string> #include <iostream> #include <algorithm> #inc…

题目链接:http://www.lydsy.com/JudgeOnline/problem.php?id=1619 题意: 给你一个n*m的地形图,位置(x,y)的海拔为h[x][y]. 一个山顶的定义为:可以是一个点,或是一片海拔相同的区域. 要求为山顶周围(每个点的八个方向)的海拔均比山顶低(或为边界). 问你有多少个山顶. 题解: dfs灌水法. 将所有点按海拔从高到低排序. 依次从每个点灌水,水流到的地方做标记. 灌水:如果一个点有水,则它周围海拔比它低的点也会被水淹. AC Code:…

不是严格小于是小于等于啊!!!!!不是严格小于是小于等于啊!!!!!不是严格小于是小于等于啊!!!!! 是我看不懂人话还是翻译不说人话= = 把所有格子按值排个序,bfs扩展打标记即可 #include<iostream> #include<cstdio> #include<algorithm> #include<queue> using namespace std; const int N=705,dx[]={-1,-1,-1,0,0,1,1,1},dy[…

描述 http://www.lydsy.com/JudgeOnline/problem.php?id=1619 给出一张图每个点的高度,在一个点上安排守卫可以监视周围所有不高于于当前点的点.也就是类似在一个点上灌水,周围(8格)低于它的点都会有水,然后继续...求最少的守卫数. 分析 首先图中的最高点必须是要灌水的,所以就从当前最高的开始宽搜,有水的点标记掉就好了. #include <bits/stdc++.h> #define fst first #define scd second us…

P2919 [USACO08NOV]守护农场Guarding the Farm 相似题:P3456 [POI2007]GRZ-Ridges and Valleys 按海拔是否相同分块 每次bfs海拔相同的块,根据与周围的块的大小关系判断是否是山丘. #include<iostream> #include<cstdio> #include<cstring> #include<queue> #include<cctype> #define re re…

P2919 [USACO08NOV]守护农场Guarding the Farm 题目描述 The farm has many hills upon which Farmer John would like to place guards to ensure the safety of his valuable milk-cows. He wonders how many guards he will need if he wishes to put one on top of each hill…