ACM PKU 1915 Knight Moves 典型的宽度优先搜索 BFS

ACM PKU 1915 Knight Moves 典型的宽度优先搜索 BFS

http://acm.pku.edu.cn/JudgeOnline/problem?id=1915
发现用vector来做宽搜的队列,要比自己弄一个队列来记录方便得多,呵呵
程序很简单,关键地方我都注释上了

Source Code

Problem:  1915   User: lnmm 
Memory: 1560K  Time: 156MS 
Language: C ++   Result: Accepted 

Source Code 
#include  < iostream >
#include  < vector >
using   namespace  std;
int   mapSize,beginX,beginY,EndX,EndY;     
int  minMoves[ 301 ][ 301 ];   
int  index;
bool  find;
struct  point  
{
    int x;
    int y;
} tempPoint; 
vector  < point >  vec;       //  灵活应用vector.push_back(),即放到队尾 (比较.push()入栈) ;用index来控制处理顺序
void  deal( int  x, int  y, int  times)
  {
     if(x==EndX&&y==EndY) 
      { 
            find=true;
            return;
     }  
    
   
      if(x-2>=0&&y-1>=0&&minMoves[x-2][y-1]==-1)            //如果 某种走法没有超过棋盘界限 且 那一格没有走过
        { 
            minMoves[x-2][y-1]=times+1;
            tempPoint.x=x-2;
            tempPoint.y=y-1;
            vec.push_back(tempPoint);
       }
      if(x-2>=0&&y+1<mapSize&&minMoves[x-2][y+1]==-1) 
         {
            minMoves[x-2][y+1]=times+1;
            tempPoint.x=x-2;
            tempPoint.y=y+1;
            vec.push_back(tempPoint);
        }
      if(x+2<mapSize&&y+1<mapSize&&minMoves[x+2][y+1]==-1) 
        {
            minMoves[x+2][y+1]=times+1;
            tempPoint.x=x+2;
            tempPoint.y=y+1;
            vec.push_back(tempPoint);
       }
      if(x+2<mapSize&&y-1>=0&&minMoves[x+2][y-1]==-1)
       {
            minMoves[x+2][y-1]=times+1;
            tempPoint.x=x+2;
            tempPoint.y=y-1;
            vec.push_back(tempPoint);       
      }
      if(x-1>=0&&y-2>=0&&minMoves[x-1][y-2]==-1)
         {
            minMoves[x-1][y-2]=times+1;
            tempPoint.x=x-1;
            tempPoint.y=y-2;
            vec.push_back(tempPoint);
        }
      if(x-1>=0&&y+2<mapSize&&minMoves[x-1][y+2]==-1) 
        {
            minMoves[x-1][y+2]=times+1;
            tempPoint.x=x-1;
            tempPoint.y=y+2;
            vec.push_back(tempPoint);
       }
      if(x+1<mapSize&&y-2>=0&&minMoves[x+1][y-2]==-1)
       {
            minMoves[x+1][y-2]=times+1;
           tempPoint.x=x+1;
            tempPoint.y=y-2;
            vec.push_back(tempPoint);
        }
      if(x+1<mapSize&&y+2<mapSize&&minMoves[x+1][y+2]==-1)
        {
            minMoves[x+1][y+2]=times+1;
            tempPoint.x=x+1;
            tempPoint.y=y+2;
            vec.push_back(tempPoint);
       }
}

int  main()
  {
 int nCase;
 cin>>nCase;
 while(nCase--)
  {
        cin>>mapSize;
        cin>>beginX>>beginY;
        cin>>EndX>>EndY;
        find=false;   //初识设置索引是0
        index=0;
        memset(minMoves,-1,sizeof(minMoves)); //设置所有点未走过
        minMoves[beginX][beginY]=0;   //设置起点已走过,步数是0
        vec.clear();
        point tempPoint;
        tempPoint.x=beginX;
        tempPoint.y=beginY;
        vec.push_back(tempPoint);
        while(index<vec.size()&&!find)   //vec里还有元素未处理完 且 没有找到   vec.size() range from 0 to vex.size-1
        {
        deal(vec[index].x,vec[index].y,minMoves[vec[index].x][vec[index].y]);
        index++;       
        } 
        cout<<minMoves[EndX][EndY]<<endl;
 }    
    
return 0;
}