CodeVS 1010 过河卒 （DFS）

题目大意：

http://codevs.cn/problem/1010/

代码：

#include <iostream>

using namespace std;

int sx,sy;
int mx,my;
int ex,ey;
int arr[100][100] = {0};
int mv[8][2] = {{-1,2},{-2,1},{1,2},{2,1},{2,-1},{-2,-1},{1,-2},{-1,-2}};
int res;

/*bool judge(int x, int y)
{
    if(x == mx && y == my)
        return false;
    int mv[8][2] = {{-1,2},{-2,1},{1,2},{2,1},{2,-1},{-2,-1},{1,-2},{-1,-2}};

    for(int i = 0; i < 8; i++)
    {
        int xx = mx + mv[i][0];
        int yy = my + mv[i][1];

        if(x == xx && y == yy)
            return false;
    }

    return true;
}*/

void dfs(int x, int y)
{
    if(x == ex && y == ey)
    {
        res++;
        return;
    }

    int mv_t[2][2] = {{1,0},{0,1}};
    for(int i = 0; i < 2; i++)
    {
        int tmpx = x+mv_t[i][0];
        int tmpy = y+mv_t[i][1];
        if(tmpx >= 0 && tmpx <= ex && tmpy >= 0 && tmpy <= ey && arr[tmpx][tmpy] != 1)
        {
            dfs(tmpx,tmpy);

        }
    }
}
int main()
{
    cin >> ex >> ey >> mx >> my;

    arr[mx][my] = 1;
    for(int i = 0; i < 8; i++)
    {
        int xx = mx + mv[i][0];
        int yy = my + mv[i][1];
        if(xx >= 0 && xx <= ex && yy >= 0 && yy <= ey)
        {
            arr[xx][yy] = 1;
        }
    }

    res = 0;
    dfs(0,0);
    cout << res << endl;


    return 0;
}