POJ-3984-迷宫问题

Posted 2021-02-03 ydddd

链接：https://vjudge.net/problem/POJ-3984

题意：

给5x5的迷宫，1不可走，0可走。

从左上角走到右下角。求最短的路径

思路：

BFS+路径记录

练习bfs的路径记录

代码：

#include <iostream>
#include <memory.h>
#include <queue>
#include <stack>
using namespace std;
typedef long long LL;
struct Node
{
    int _x,_y;
    Node(int x,int y)
    {
        _x = x;
        _y = y;
    }
    Node(){}
}last[5][5];
const int Next[4][2] = {{-1,0},{0,1},{1,0},{0,-1}};
int Map[5][5];
int vis[5][5];

int main()
{
    for (int i = 0;i<5;i++)
        for (int j = 0;j<5;j++)
            scanf("%d",&Map[i][j]);
    queue<Node> que;
    que.push(Node(0,0));
    vis[0][0] = 1;
    while (!que.empty())
    {
        int x = que.front()._x;
        int y = que.front()._y;
        if (x == 4&&y == 4)
            break;
        for (int i = 0;i<4;i++)
        {
            int nx = x+Next[i][0];
            int ny = y+Next[i][1];
            if (nx < 0||nx > 4||ny < 0||ny > 4||vis[nx][ny] == 1||Map[nx][ny] == 1)
                continue;
            last[nx][ny]._x = x;
            last[nx][ny]._y = y;
            que.push(Node(nx,ny));
            vis[nx][ny] = 1;
        }
        que.pop();
    }
    stack<Node> Path;
    int px = 4,py = 4;
    while (px != 0||py != 0)
    {
        Path.push(Node(px,py));
        int tx = last[px][py]._x;
        int ty = last[px][py]._y;
        px = tx;
        py = ty;
    }
    Path.push(Node(0,0));
    while (Path.size())
    {
        printf("(%d, %d)
",Path.top()._x,Path.top()._y);
        Path.pop();
    }

    return 0;
}