"Bzoj 3299" [USACO2011 open]corn Maze corn maze (shortest way)

One is the shortest, and the edge length is 1, so each point is searched only once.

1 /**************************************************************2 problem:32993 User:mt_chan4 language:c++5 result:accepted6 time:72 Ms7 memory:2420 KB8 ****************************************************************/9  Ten#include <cstdio> One#include <cstdlib> A#include <cstring> -#include <iostream> -#include <algorithm> the#include <queue> - using namespacestd; - #defineMAXN 310 - #defineINF 0XFFFFFFF +   - intkx[ -]; + inta[maxn][maxn],tr[maxn*MAXN]; A CharS[MAXN]; at   - intdis[maxn*maxn],st,ed; - intn,m; -   -queue<int>Q; - voidSPFA () in { -      while(!q.empty ()) Q.pop (); tomemset (dis,-1,sizeof(DIS)); +Q.push (ST);d is[st]=0; -      while(!q.empty ()) the     { *         intx=Q.front (); $         intnx= (x1)/m+1, ny=x-(nx-1)*m;Panax Notoginseng         if(ny>1&&tr[x-1]!=-1&&dis[tr[x-1]]==-1) -         { thedis[tr[x-1]]=dis[x]+1; +             if(tr[x-1]==ed) Break; AQ.push (tr[x-1]); the         } +         if(ny<m&&tr[x+1]!=-1&&dis[tr[x+1]]==-1) -         { $dis[tr[x+1]]=dis[x]+1; $             if(tr[x+1]==ed) Break; -Q.push (tr[x+1]); -         } the         if(nx>1&&tr[x-m]!=-1&&dis[tr[x-m]]==-1) -         {Wuyidis[tr[x-m]]=dis[x]+1; the             if(tr[x-m]==ed) Break; -Q.push (tr[x-m]); Wu         } -         if(nx<n&&tr[x+m]!=-1&&dis[tr[x+m]]==-1) About         { $dis[tr[x+m]]=dis[x]+1; -             if(tr[x+m]==ed) Break; -Q.push (tr[x+m]); -         } A Q.pop (); +     } theprintf"%d\n", dis[ed]); - } $   the intMain () the { thescanf"%d%d",&n,&m); thememset (kx,-1,sizeof(KX)); -memset (TR,0,sizeof(tr)); in      for(intI=1; i<=n;i++) the     { thescanf"%s", s); About          for(intj=0; j<m;j++) the         { the             intnow= (I-1) *m+j+1; the             if(s[j]=='@') st=Now ; +             Else if(s[j]=='=') ed=Now ; -             Else if(s[j]=='#') tr[now]=-1; the             Else if(s[j]>='A'&&s[j]<='Z')Bayi             { the                 intkk=s[j]-'A'+1; the                 if(kx[kk]==-1) kx[kk]=Now ; -                 Elsetr[now]=kx[kk],tr[kx[kk]]=Now ; -             } the         } the     } the      for(intI=1; i<=n*m;i++)if(tr[i]==0) tr[i]=i; the SPFA (); -     return 0;  the}

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"Bzoj 3299" [USACO2011 open]corn Maze corn maze (shortest way)