简单回溯，最少步数

题目链接：http://acm.nyist.net/JudgeOnline/problem.php?pid=58

#include <stdio.h>
#include <string.h>
#include <algorithm>
#define INF 0x3f3f3f3f


using namespace std;

int MAPN[9][9]=
{
    {1,1,1,1,1,1,1,1,1},
    {1,0,0,1,0,0,1,0,1},
    {1,0,0,1,1,0,0,0,1},
    {1,0,1,0,1,1,0,1,1},
    {1,0,0,0,0,1,0,0,1},
    {1,1,0,1,0,1,0,0,1},
    {1,1,0,1,0,1,0,0,1},
    {1,1,0,1,0,0,0,0,1},
    {1,1,1,1,1,1,1,1,1},
};

int color[9][9];

int mov[4][2]= {{1,0},{-1,0},{0,1},{0,-1}};



int dfs(int sx,int sy,int x,int y)
{
    int step=INF;
    if(sx==x&&sy==y)
        return 0;
    else
    {
        for(int k=0; k<4; k++)
        {
            int tx=sx+mov[k][0];
            int ty=sy+mov[k][1];

            if(tx>=0&&tx<=8&&ty>=0&&ty<=8)
            {
                if(!color[tx][ty]&&!MAPN[tx][ty])
                {
                    color[tx][ty]=1;
                    step=min(step,dfs(tx,ty,x,y)+1);
                    color[tx][ty]=0;
                }
            }
        }
        return step;
    }
}

int main()
{
    int sx,sy,x,y;///起始位置，目标位置。
    int t;
    scanf("%d",&t);
    while(t--)
    {
        memset(color,0,sizeof(color));

        scanf("%d%d%d%d",&sx,&sy,&x,&y);
        printf("%d
",dfs(sx,sy,x,y));
    }

    return 0;
}