迷宫递归算法

迷宫，递归实现：

/*
    迷宫之递归，能够输出所有的路线。
*/
#include <iostream>
#include <time.h>
using namespace std;
typedef struct Position{
    int x;
    int y;
}POSITION,*pPOSiTION;

int MazeMapLineNumber =0;
pPOSiTION pMazePath;
int PathLength = 0;
bool IsOutOfBorder(int x,int y);
void Go(pPOSiTION pos);//将当前位置放入迷宫路线中
void Try(int **pMap,pPOSiTION begin,pPOSiTION end);//开始找路
bool Showpath();
int main() {
    int **pMap = NULL;
    pPOSiTION begin = new POSITION;
    pPOSiTION end = new POSITION;
    int i=0,j=0;
    srand((unsigned)time(NULL));
    cout<<"Please input the row of the maze map:";
    cin>>MazeMapLineNumber;
    pMap = new int *[MazeMapLineNumber];
    for (i=0;i<MazeMapLineNumber;i++) {
        pMap[i] = new int [MazeMapLineNumber];
    }

    //动态生成一个二维数组，用于地图
    for (i=0;i<MazeMapLineNumber;i++) {
        for (j=0;j<MazeMapLineNumber;j++) {
            pMap[i][j] = rand()%2;
            cout<<pMap[i][j]<<" ";
        }
        cout<<"\n";
    }
    cout<<endl;
    //该for循环主要输出对应点的坐标，节省输入时间。
    for (i=0;i<MazeMapLineNumber;i++) {     
        for (j=0;j<MazeMapLineNumber;j++) {
            cout<<pMap[i][j]<<"("<<i<<","<<j<<")"<<" ";
        }
        cout<<"\n";
    }
    pMazePath = new POSITION[MazeMapLineNumber*MazeMapLineNumber];
    cout<<"Please input start's x and y:";
    cin>>begin->x>>begin->y;
    cout<<"Please input end's x and y:";
    cin>>end->x>>end->y;
    Go(begin);
    pMap[begin->x][begin->y] = 0;
    Try(pMap,begin,end);

    if(PathLength == 0) cout<<"There is no way to pass the maze"<<endl;
    return 0;
}



bool IsOutOfBorder(int x,int y) {
    if(x<0||x>=MazeMapLineNumber||y<0||y>=MazeMapLineNumber) return true;
    else return false;
}

void Go(pPOSiTION pos){
    pMazePath[PathLength].x=pos->x;
    pMazePath[PathLength].y=pos->y;
    PathLength++;
}
void Try(int **pMap,pPOSiTION begin,pPOSiTION end) {
    POSITION NextPos[4] = {{0,1},{1,0},{0,-1},{-1,0}};
    pPOSiTION next = new POSITION;
    next->x = begin->x;
    next->y = begin->y;
    //cout<<"next1:"<<next->x<<","<<next->y<<endl;    //方便调试。。下同
    int i=0;
    if(next->x==end->x && next->y==end->y) {
        Showpath();
    } else {
        for (i=0;i<4;i++) {
            //cout<<"begin1:"<<begin->x<<","<<begin->y<<endl;  
            next->x =begin->x + NextPos[i].x;
            next->y =begin->y + NextPos[i].y;
            //cout<<"begin2:"<<begin->x<<","<<begin->y<<endl;
            if(!IsOutOfBorder(next->x,next->y)&&pMap[next->x][next->y]==1) {
                Go(next);
                pMap[next->x][next->y] = 0;//将当前的点置为不可行
                //cout<<"next2:"<<next->x<<","<<next->y<<endl;
                Try(pMap,next,end);
                pMap[next->x][next->y] = 1;//恢复可行，让下一次可以使用该点
                PathLength--;//迷宫路线长度-1，代表该路线已经探索完毕。
            }
        }
    }

}

bool Showpath() {
    static int num;
    if(PathLength == 0) {
        cout<<"There is no way to pass the maze"<<endl;
        return false;
    }
    cout<<"Path"<<num++<<":"<<endl;
    for(int i=0;i<PathLength-1;i++) {
        cout<<"("<<pMazePath[i].x<<","<<pMazePath[i].y<<")"<<"->";
    }
    cout<<"("<<pMazePath[PathLength-1].x<<","<<pMazePath[PathLength-1].y<<")"<<endl;
    return true;
}

之前用栈写了一个迷宫，但是无法输出全部路线，现在学到递归函数了，发现能够全部输出全部的路线
递归虽然占用资源，但是用起来却是很方便。一步一步踏踏实实的向前进行！加油！

顺带一个汉诺塔的小函数,同样是递归

/*
汉诺塔算法：1：将A上的n-1个盘子借助C移到B上。
            2：将A上的第n个盘子移到C上。
            3：将B上的n-1盘子借助A移到C上。
*/
#include <stdio.h>
void game(int n,char A,char B,char C);//将A上的盘子借助B移动到C
int main() {
    char A = 'A',B='B',C='C';
    game(2,A,B,C);
    return 0;
}

void game(int n,char A,char B,char C) {
    if(1 == n) {
        printf("Please put plate %d to %c from %c \n",n,C,A);
    } else {
        game(n-1,A,C,B);
        printf("Please put plate %d to %c from %c \n",n,C,A);
        game(n-1,B,A,C);    
    }    
}

上述两个应该都算入门级递归算法吧。为以后学习树和图打下好的基础吧。。。加油！