POJ 1979 Red and Black

http://poj.org/problem?id=1979

方法和Lake Counting 完全一样

#include <iostream>
#include <stdio.h>

using namespace std;
//思路与Lake counting 完全一样
const int maxsize = 128;
int M,N,cnt;
char room[maxsize][maxsize];
int d[2][4] = {{-1, 0, 1, 0}, {0, 1, 0, -1}};

bool check(int x, int y)
{
    if (x < 0 || x >= N || y < 0 || y >= M) return false;
    if (room[x][y] == '#') return false;
    return true;
}

void dfs(int x, int y)
{
    int nx, ny;
    room[x][y] = '#';//将这个格置为#
    for (int i = 0; i < 4; i++)
    {
        nx = x + d[0][i];
        ny = y + d[1][i];
        if (check(nx, ny))
        {
            cnt++;
            dfs(nx, ny);
        }
    }
}

int main()
{
    int x,y;
    freopen("in.txt", "r", stdin);
    while(~scanf("%d%d", &M, &N))
    {
        if (M == 0 && N == 0) break;
        for (int i = 0; i < N; i++)
        {
            getchar();
            for (int j = 0; j < M; j++)
            {
                scanf("%c", &room[i][j]);
                if (room[i][j] == '@')
                {
                    x = i;
                    y = j;
                }
            }
        }
        cnt = 1;
        dfs(x, y);
        printf("%d
", cnt );
    }
    return 0;
}