BFS迷宫问题

  1 #include<graphics.h>
  2 #include<stdlib.h>
  3 #include<conio.h>
  4 #include<time.h>
  5 #include<vector>
  6 #include<queue>
  7 #include<stack>
  8 #include<iostream>
  9 #include <algorithm>
 10
 11 using namespace std;
 12
 13 struct point{
 14     //横坐标纵坐标
 15     int x;
 16     int y;
 17 };
 18 int **Maze;     //初始化迷宫
 19 point **Pre;    //保存任意点在路径中的前一步
 20 point move[8]={{-1,-1},{-1,0},{-1,1},{0,-1},{0,1},{1,-1},{1,0},{1,1}}; //移动方向，横竖斜都可以，八个方向
 21 char s1[]="YES";
 22 char s2[]="NO";
 23
 24 void create_line(int row ,int  column)//划线
 25 {
 26   int x, y;  // 画格子
 27    for (x=0; x<=10*(row+2); x+=10)
 28         for (y=0; y<=10*(column+2); y+=10)
 29         {
 30             line(x, 0, x, 10*(column+2));
 31             line(0, y,10*(row+2), y);
 32         }
 33 }
 34
 35
 36 void CreateTable(int row,int column)//初始化创建迷宫障碍区
 37 {
 38     int i,j;
 39     srand((unsigned int)time(NULL));
 40     for(i=0; i<row+2; i++)//创建迷宫，注意到用0表示可走，1表示墙，将整个输入的迷宫再用墙围着，处理的时候就不用特别注意边界问题
 41     {
 42         Maze[i][0] = Maze[i][column+1] = 1;
 43     }
 44     for(j=0; j<column+2; j++)
 45     {
 46         Maze[0][j] = Maze[row+1][j] = 1;
 47     }
 48
 49     for(i=1;i<=row;i++)
 50      for(j=1;j<=column;j++)
 51         {
 52              Maze[i][j]=rand()%2;
 53         }
 54
 55    for(i=1;i<=row;i++)
 56      for(j=1;j<=column;j++)
 57         {
 58              if(Maze[i][j]==1)
 59             Maze[i][j]=rand()%2;
 60         }
 61
 62     for(i=0;i<=row+1;i++)
 63      for(j=0;j<=column+1;j++)
 64      {
 65          if(Maze[i][j]==1)
 66         {
 67          setfillcolor(WHITE);
 68          fillrectangle(10*j,(10+10*i),(10+10*j),10*i);
 69         }
 70      }
 71 }
 72
 73 bool MazePath(int row,int column,int x,int y){
 74     //判断是否有路径从入口到出口，保存该路径（队列）
 75     if(x == row && y == column)return true;
 76     queue<point> q;     //用于广度优先搜索
 77     point now;          //当前位置
 78     now.x = x;
 79     now.y = y;
 80     q.push(now);
 81     Maze[now.x][now.y] = -1;
 82     while(!q.empty()){
 83         now = q.front();
 84         q.pop();
 85         for(int i=0; i<8; i++){
 86             if(now.x + move[i].x == row && now.y + move[i].y == column){
 87                 Maze[now.x + move[i].x][now.y + move[i].y] = -1;
 88                 Pre[row][column] = now;
 89                 return true;
 90             }
 91             if(Maze[now.x + move[i].x][now.y + move[i].y] == 0){
 92                 point temp;     //下个位置
 93                 temp.x = now.x + move[i].x;
 94                 temp.y = now.y + move[i].y;
 95                 q.push(temp);
 96                 Maze[temp.x][temp.y] = -1;
 97                 Pre[temp.x][temp.y] = now;
 98
 99             }
100         }
101     }
102     return false;
103 }
104
105
106 void PrintPath(int row,int column){
107     //输出最短路径
108     point temp;         //保存位置
109     stack<point> s;     //保存路径序列
110     temp.x = row;
111     temp.y = column;
112     while(temp.x != 1 || temp.y != 1){
113         s.push(temp);
114         temp = Pre[temp.x][temp.y];
115     }
116        setfillcolor(YELLOW);
117        fillrectangle(10*1,(10+10*1),(10+10*1),10*1);
118     while(!s.empty()){
119         temp = s.top();
120         setfillcolor(YELLOW);
121         fillrectangle(10*temp.y,(10+10*temp.x),(10+10*temp.y),10*temp.x);
122         s.pop();
123     }
124     cout<<endl;
125 }
126
127 void result(int row,int column)
128 {
129   if(MazePath(row,column,1,1))
130   {
131             //outtextxy(320,320,s1);
132             PrintPath(row,column);
133   }
134         else outtextxy(320,320,s2);
135 }
136
137 void Init(int row,int column)
138 {
139  Maze = new int*[row + 2];
140  Pre = new point*[row + 2];
141  for(int i=0; i<row+2; i++)
142  {
143  Maze[i] = new int[column + 2];
144  Pre[i] = new point[column + 2];
145  }
146 }
147
148 void main()
149 {
150 int row,column;
151 cin>>row>>column;
152 Init(row,column);
153 initgraph(640,640);
154 BeginBatchDraw();
155 setlinecolor(GREEN);//设置字体颜色
156 create_line(column,row);
157 CreateTable(row,column);
158 result(row,column);
159 FlushBatchDraw();
160 EndBatchDraw();
161 getch();
162 closegraph();
163 }