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;
}

posted on 2007-11-16 15:37 流牛ζ木马 阅读(2930) 评论(0)  编辑 收藏 引用


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