Red and Black
| Time Limit: 1000MS | Memory Limit: 30000K | |
| Total Submissions: 27891 | Accepted: 15142 |
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.
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.
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
1 #include <cstdio> 2 #include <algorithm> 3 #include <iostream> 4 #include <cstring> 5 #include <queue> 6 using namespace std; 7 char map[25][25]; 8 bool vis[25][25]; 9 int dx[4]={0,0,1,-1},dy[4]={1,-1,0,0}; 10 int w,h; 11 int sx,sy; 12 struct node 13 { 14 int x,y; 15 }; 16 int bfs() 17 { 18 queue<node> q; 19 int ans=0; 20 memset(vis,0,sizeof(vis)); 21 node s,temp; 22 s.x=sx,s.y=sy; 23 q.push(s); 24 while(!q.empty()) 25 { 26 s=q.front(); 27 q.pop(); 28 ans++; 29 for(int i=0;i<4;i++) 30 { 31 temp.x=s.x+dx[i]; 32 temp.y=s.y+dy[i]; 33 if(temp.x>=0&&temp.x<h&&temp.y>=0&&temp.y<w&&vis[temp.x][temp.y]==0&&map[temp.x][temp.y]=='.') 34 { 35 36 vis[temp.x][temp.y]=1; 37 q.push(temp); 38 39 } 40 } 41 } 42 return ans; 43 } 44 int main() 45 { 46 int i,j; 47 freopen("in.txt","r",stdin); 48 while(scanf("%d%d",&w,&h)) 49 { 50 if(w==0&&h==0) 51 break; 52 for(i=0;i<h;i++) 53 scanf("%s",map[i]); 54 for(i=0;i<h;i++) 55 for(j=0;j<w;j++) 56 if(map[i][j]=='@') 57 { 58 sx=i,sy=j; 59 break; 60 } 61 62 cout<<bfs()<<endl; 63 } 64 return 0; 65 }