poj 2488 A Knight's Journey

poj 2488 A Knight's Journey

http://acm.pku.edu.cn/JudgeOnline/problem?id=2488
poj 2488 A Knight's Journey
简单的BFS

Source Code

Problem: 2488		User: lovecanon
Memory: 324K		Time: 16MS
Language: GCC		Result: Accepted

• Source Code

  
      
        
        
        
        
   
         #include<stdio.h>
  #include<string.h>
  
  
  typedef struct node
  {
   int r;
   int c;
  }node;
  node step[50];
  
  int m,n,found;
  const int dx[]={-2,-2,-1,-1,1,1,2,2},dy[]={-1,1,-2,2,-2,2,-1,1};
  
  int visited[50][50],dep;
  
  int ok(int r,int c)
  {
   if(r>=1&&r<=m&&c>=1&&c<=n) return 1;
   return 0;
  }
  
  void output()
  {
   int i;
   if(found==0) { printf("impossible\n\n");return; }
   for(i=1;i<=m*n;i++)
   printf("%c%d",step[i].r-1+'A',step[i].c);
   printf("\n\n");
  
  }
  
  void solve(int r,int c){
   if(!found){
   visited[r][c]=1;
   step[dep].r=r;
   step[dep].c=c;
   
   if(dep>=m*n){
   found=1;return;
   }
   
   else{
   int nextr,nextc,i;
   for(i=0;i<8;i++)
   {
   nextr=r+dx[i];
   nextc=c+dy[i];
   if(ok(nextr,nextc)&&!visited[nextr][nextc])
   {
   dep++;
   solve(nextr,nextc);
   dep--;
   }
   }
   visited[r][c]=0;
   }
   }
   
  }
  
  int main()
  {
   int T,count=1;
   scanf("%d",&T);
   while(count<=T)
   {
   scanf("%d%d",&n,&m);
   dep=1;found=0 ;
   memset(visited,0,sizeof(visited));
   solve(1,1);
   printf("Scenario #%d:\n",count);
   output();
   count++;
   }
   return 0;
  }