POJ 1979 Red and Black
阿新 • • 發佈:2018-04-29
水題 IT sin earch contain tput scanf sample eating Red and Black
Write a program to count the number of black tiles which he can reach by repeating the moves described above.
There are H more lines in the data set, each of which includes W characters. Each character represents the color of a tile as follows.
‘.‘ - a black tile
‘#‘ - a red tile
‘@‘ - a man on a black tile(appears exactly once in a data set)
The end of the input is indicated by a line consisting of two zeros.
Time Limit: 1000MS | Memory Limit: 30000K | |
Total Submissions: 41222 | Accepted: 22338 |
Description
There is a rectangular room, covered with square tiles. Each tile is colored either red or black. A man is standing on a black tile. From a tile, he can move to one of four adjacent tiles. But he can‘t move on red tiles, he can move only on black tiles.Write a program to count the number of black tiles which he can reach by repeating the moves described above.
Input
The input consists of multiple data sets. A data set starts with a line containing two positive integers W and H; W and H are the numbers of tiles in the x- and y- directions, respectively. W and H are not more than 20.There are H more lines in the data set, each of which includes W characters. Each character represents the color of a tile as follows.
‘.‘ - a black tile
‘#‘ - a red tile
‘@‘ - a man on a black tile(appears exactly once in a data set)
The end of the input is indicated by a line consisting of two zeros.
Output
For each data set, your program should output a line which contains the number of tiles he can reach from the initial tile (including itself).Sample Input
6 9
....#.
.....#
......
......
......
......
......
#@...#
.#..#.
11 9
.#.........
.#.#######.
.#.#.....#.
.#.#.###.#.
.#.#..@#.#.
.#.#####.#.
.#.......#.
.#########.
...........
11 6
..#..#..#..
..#..#..#..
..#..#..###
..#..#..#@.
..#..#..#..
..#..#..#..
7 7
..#.#..
..#.#..
###.###
...@...
###.###
..#.#..
..#.#..
0 0
Sample Output
45
59
6
13
Source
Japan 2004 Domestic 思路:水題,bfs即可。#include<queue> #include<cstdio> #include<cstring> #include<iostream> #include<algorithm> using namespace std; int map[21][21]; int w,h,sx,sy,ans; int dx[4]={1,-1,0,0}; int dy[4]={0,0,1,-1}; struct nond{ int x,y; }; int main(){ while(scanf("%d%d",&w,&h)&&w!=0&&h!=0){ swap(w,h); for(int i=1;i<=w;i++) for(int j=1;j<=h;j++){ char x;cin>>x; if(x==‘.‘) map[i][j]=0; else if(x==‘#‘) map[i][j]=1; else if(x==‘@‘){ sx=i;sy=j;map[i][j]=0; } } queue<nond>que;ans=1; nond tmp;tmp.x=sx;tmp.y=sy; que.push(tmp);map[sx][sy]=1; while(!que.empty()){ nond now=que.front(); que.pop(); for(int i=0;i<4;i++){ int cx=dx[i]+now.x; int cy=dy[i]+now.y; if(cx>=1&&cx<=w&&cy>=1&&cy<=h&&!map[cx][cy]){ map[cx][cy]=1; nond mid;mid.x=cx;mid.y=cy; que.push(mid);ans++; //cout<<cx<<" "<<cy<<endl; } } } cout<<ans<<endl; } }
POJ 1979 Red and Black