Red and Black
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 5175 Accepted Submission(s): 3370
Problem 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)
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)
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
#include <iostream>
#include <cstring>
using namespace std;
#pragma warning(disable : 4996)
#define MAX 25
char maps[MAX][MAX];
int w, h, ans;
const int moves[4][2] = {{0, -1}, {0, 1}, {1, 0}, {-1, 0}};
void dfs(int x, int y)
{
maps[x][y] = '#';
for(int i = 0; i < 4; i++)
{
int p = x + moves[i][0];
int q = y + moves[i][1];
if(p >= 1 && p <= h && q >= 1 && q <= w && maps[p][q] == '.')
{
maps[p][q] = '#';
ans++;
dfs(p, q);
}
}
}
int main()
{
freopen("in.txt", "r", stdin);
int x, y;
while (cin >>w >> h)
{
if(w == 0 && h == 0)
{
break;
}
for(int i = 1; i <= h; i++)
{
for(int j = 1; j <= w; j++)
{
cin >> maps[i][j];
if(maps[i][j] == '@')
{
x = i;
y = j;
}
}
}
ans = 1;
dfs(x, y);
cout << ans << endl;
}
return 0;
}