数据结构实习

#include <iostream>
#include <windows.h>
#include <cstdio>
#include <cmath>
#include <time.h>
#include <cstring>

using namespace std;

const int N = 1000;
int fa[N], len_path, maze[N][N], book[N][N];
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};

void init()
{
    for(int i = 0; i < N; i++)
        fa[i] = i;
}

int getfa(int x)
{
    if(fa[x] == x)return x;
    else return fa[x] = getfa(fa[x]);
}

void Merge(int a, int b)
{
    int af = getfa(a);
    int bf = getfa(b);
    if(af != bf)
        fa[bf] = af;
}

int tolist(int x, int y, int n)
{
    return x*n+y;
}

void print(int n)
{
    for(int i = 0; i < n; i++)
    {
        for(int j = 0; j < n; j++)
            cout<<maze[i][j]<<" ";
        cout<<endl;
    }
}

void mazeInit(int n)
{
    int sx, sy, ex, ey, x, y;
    init();
    for(int i = 0; i < n; i++)
        for(int j = 0; j < n; j++)
            maze[i][j] = 1;
    for(int i = 1; i < n; i++)
    {
        if(i&1)
            for(int j = 1; j < n; j+=2)
                maze[i][j] = 0;
    }
    print(n);
    cout<<"*********************"<<endl;
    srand(time(NULL));
    int d;
    int tx1, ty1, tx2, ty2;
    sx = sy = 1;
    ex = ey = n-3;

    // sx = rand()%(n-2)+1;
    // sy = rand()%(n-2)+1;
    // do
    // {
    //     ex = rand()%(n-2)+1;
    //     ey = (rand()+2333)%(n-2)+1;
    // }while(sx!=ex && sy!=ey);
    cout<<"ok"<<endl;
    maze[sx][sy] = maze[ex][ey] = 0;
    while(getfa(tolist(sx, sy, n)) != getfa(tolist(ex, ey, n)))
    {
        do
        {
            x = rand()%(n-2)+1;
            y = (rand()+2333)%(n-2)+1;
        }
        while(maze[x][y] != 1);
        d = x%2;
        if(!d)
        {
            tx1 = x+1;
            ty1 = y;
            tx2 = x-1;
            ty2 = y;
            if(getfa(tolist(tx1, ty1, n)) != getfa(tolist(tx2, ty2, n)))
            {
                maze[x][y] = 0;
                Merge(tolist(tx1, ty1, n), tolist(tx2, ty2, n));
            }
        }
        else
        {
            tx1 = x;
            ty1 = y+1;
            tx2 = x;
            ty2 = y-1;
            if(getfa(tolist(tx1, ty1, n)) != getfa(tolist(tx2, ty2, n)))
            {
                maze[x][y] = 0;
                Merge(tolist(tx1, ty1, n), tolist(tx2, ty2, n));
            }
        }
    }
    for(int i = 0; i < n; i++)
    {
        maze[i][n-1] = 1;
        maze[n-1][i] = 1;
    }
    maze[sx][sy] = 2;
    maze[ex][ey] = 3;
    print(n);
}

struct point
{
    int x, y, pre;
}q[N], path[N];

void getPath(int pos)
{
    while(pos != -1)
    {
        path[len_path].x = q[pos].x;
        path[len_path].y = q[pos].y;
        len_path++;
        pos = q[pos].pre;
    }
}

void bfs(int n)
{
    int front, tail, sx, sy, ex, ey;
    for(int i = 0; i < n; i++)
        for(int j = 0; j < n; j++)
            if(maze[i][j] == 2)
            {
                sx = i; sy = j;
            }
    front = tail = 0;
    q[tail].x = sx;
    q[tail].y = sy;
    q[tail].pre = -1;
    tail++;
    int x, y, nx, ny;
    bool fg = false;
    while(front < tail)
    {
        x = q[front].x;
        y = q[front].y;
        for(int i = 0; i < 4; i++)
        {
            nx = x+dx[i];
            ny = y+dy[i];
            if(nx>=0&&nx<n&&ny>=0&&ny<n&&maze[nx][ny]==0)
            {
                maze[nx][ny] = 1;
                q[tail].x = nx;
                q[tail].y = ny;
                q[tail].pre = front;
                tail++;
            }
            if(maze[nx][ny] == 3){
                q[tail].x = nx;
                q[tail].y = ny;
                q[tail].pre = front;
                tail++;
                fg = true;
                len_path = 0;
                path[len_path].x = nx;
                path[len_path].y = ny;
                len_path++;
                getPath(front);
            }
        }
        if(fg)break;
        front++;
    }
}

void printPath()
{
    for(int i = len_path-1; i >= 0; i--)
        cout<<path[i].x<<" "<<path[i].y<<endl;
}

int main()
{
    int n = 10;
    mazeInit(n);
    bfs(n);
    printPath();
    return 0;
}