1979:Red and Black http://poj.grids.cn/practice/1979

Red_and_Black.cpp

/*************************************************************************
Author: logicmd
Created Time: 2012/10/17 13:16:31
File Name: RedAndBlack.cpp
Description:
************************************************************************/

#include <cassert>
#include <iostream>
#include <vector>
#include <map>
#include <cstdio>
#include <string>
#include <utility>
#include <algorithm>

#define MAX_SIZE 20

using namespace std;

int maze[MAX_SIZE][MAX_SIZE];
int W, H;
//int direction[4][2] = {{0,1},{1,0},{0,-1},{-1,0}};

int dfs(int i, int j)
{
    if( i<0 || i>=H || j<0 || j>=W )
        return 0;
    if( maze[i][j] == -1 )
        return 0;
    maze[i][j] = -1;
    return(1+dfs(i+1,j)+dfs(i-1,j)+dfs(i,j+1)+dfs(i,j-1));
}

int main()
{
    vector<int> re;

    while(true)
    {
        cin >> W >> H;
        if(W==0&&H==0)
            break;
        char c;
        int si, sj;
        for(int i=0; i<H; i++)
        {
            for(int j=0; j<W; j++)
            {
                cin >> c;
                if(c == '.')
                    maze[i][j]=0;
                else if(c == '#')
                    maze[i][j]=-1;
                else if(c == '@')
                {
                    si = i;
                    sj = j;
                    maze[i][j] = 0;
                }
            }
        }
        int sum = dfs(si, sj);
        re.push_back(sum);
    }

    for(vector<int>::iterator its = re.begin(); its != re.end(); its++)
    {
        cout << *(its) << endl;
    }
    //system("PAUSE");

    return 0;

}