Maze of Genius (bfs+ record Path)

1 //to find the shortest distance from (sx.sy) to (gx.gy);2 3#include <iostream>4#include <cstdio>5#include <cstdio>6#include <queue>7#include <cstring>8 #defineINF 999999999 Ten using namespacestd; One  Atypedef pair<int,int> P;//number of pairs, record location - intN,m,cur;//Scale Size - intSx,sy;//Start coordinates the intGx,gy;//End coordinates - intdis[501][501];///an array of the shortest distances to each location; - intmaze[501][501];//Show Maze - intdx[4]={1,0,-1,0};//Vector in four directions + intdy[4]={0,1,0,-1};//Vector in four directions - structnode{ +     intx, y; A}pre[501][501];//Recording precursor at  -  - intBFS ()//Breadth Search - { -Queue<p>que;  -      for(intI=1; i<=n;i++) in          for(intj=1; j<=m;j++) -dis[i][j]=INF; toQue.push (P (1,1));//Join the start queue +dis[1][1]=0;//added queue distance has, the representative visited the -      the     //keep looping until the queue length is 0 *      while(Que.size ()) $     {Panax NotoginsengP p=Que.front (); Que.pop (); -         if(p.first==n&&p.second==m) the              Break; +          for(intI=0;i<4; i++)//Four Directions Access A         { the             intNx=p.first+dx[i],ny=p.second+dy[i];//represents the point that will be visited +              -             if(1<=nx&&nx<=n&&1<=ny&&ny<=m&&maze[nx][ny]==0&&dis[nx][ny]==INF) $             { $Que.push (P (Nx,ny)); dis[nx][ny]=dis[p.first][p.second]+1;//Qualifying Join Queue -Pre[nx][ny].x=p.first; Pre[nx][ny].y=p.second;//Recording precursor -             } the              -         }Wuyi     } the     returnDis[n][m]; -      Wu } - voidPrint_road (intXintY//Write a precursor About { $     if(pre[x][y].x==-1) -     return ; - print_road (PRE[X][Y].X,PRE[X][Y].Y); -     if(x==pre[x][y].x&&y>pre[x][y].y) Aprintf"R"); +     Else if(x>pre[x][y].x&&y==pre[x][y].y) theprintf"D"); -     Else    if(x<pre[x][y].x&&y==pre[x][y].y) $printf"U"); the     Else     if(x==pre[x][y].x&&y<pre[x][y].y) theprintf"L"); the } the intMain () - { in     //int n,m; the      while(~SCANF ("%d%d",&n,&m)) the     { Aboutpre[1][1].x=pre[1][1].y=-1; the          for(intI=1; i<=n;i++) the              for(intj=1; j<=m;j++) thescanf"%1d",&maze[i][j]); +Cur=BFS (); -printf"%d\n", cur); thePrint_road (N,M);//Print PathBayi     } the}

bfs+ Record precursor

Maze of Genius (bfs+ record Path)