hdu 1162 Eddy's picture

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 1554    Accepted Submission(s): 677

本题非常简单，最小生成树问题，直接抄模板即可

代码：

  
    

   
     
   
      1 
   
     #include
   
     <
   
     stdio.h
   
     >
   
     

   
      2 
   
     #include
   
     <
   
     math.h
   
     >
   
     

   
      3 
   
      
   
     struct
   
      node

   
      4 
   
     {

   
      5 
   
      
   
     double
   
      x,y;

   
      6 
   
     }s[
   
     105
   
     ];

   
      7 
   
      
   
     int
   
      n;

   
      8 
   
      
   
     double
   
      prim(
   
     int
   
      v0)

   
      9 
   
     {

   
     10 
   
      
   
     int
   
      i,j,visit[
   
     105
   
     ],u;

   
     11 
   
      
   
     double
   
      sum
   
     =
   
     0
   
     ,min,distance[
   
     105
   
     ],s1;

   
     12 
   
      
   
     for
   
     (i
   
     =
   
     1
   
     ;i
   
     <=
   
     n;i
   
     ++
   
     )

   
     13 
   
      {

   
     14 
   
      distance[i]
   
     =
   
     sqrt((s[v0].x
   
     -
   
     s[i].x)
   
     *
   
     (s[v0].x
   
     -
   
     s[i].x)
   
     +
   
     (s[v0].y
   
     -
   
     s[i].y)
   
     *
   
     (s[v0].y
   
     -
   
     s[i].y));

   
     15 
   
      visit[i]
   
     =
   
     0
   
     ;

   
     16 
   
      }

   
     17 
   
      visit[v0]
   
     =
   
     1
   
     ;

   
     18 
   
      
   
     for
   
     (i
   
     =
   
     1
   
     ;i
   
     <
   
     n;i
   
     ++
   
     )

   
     19 
   
      {

   
     20 
   
      min
   
     =
   
     0xfffffff
   
     ;

   
     21 
   
      
   
     for
   
     (j
   
     =
   
     1
   
     ;j
   
     <=
   
     n;j
   
     ++
   
     )

   
     22 
   
      {

   
     23 
   
      
   
     if
   
     (
   
     !
   
     visit[j] 
   
     &&
   
      distance[j]
   
     <
   
     min)

   
     24 
   
      {

   
     25 
   
      u
   
     =
   
     j;

   
     26 
   
      min
   
     =
   
     distance[j];

   
     27 
   
      }

   
     28 
   
      }

   
     29 
   
      sum
   
     +=
   
     min;

   
     30 
   
      visit[u]
   
     =
   
     1
   
     ;

   
     31 
   
      
   
     for
   
     (j
   
     =
   
     1
   
     ;j
   
     <=
   
     n;j
   
     ++
   
     )

   
     32 
   
      {

   
     33 
   
      s1
   
     =
   
     sqrt((s[u].x
   
     -
   
     s[j].x)
   
     *
   
     (s[u].x
   
     -
   
     s[j].x)
   
     +
   
     (s[u].y
   
     -
   
     s[j].y)
   
     *
   
     (s[u].y
   
     -
   
     s[j].y));

   
     34 
   
      
   
     if
   
     (
   
     !
   
     visit[j] 
   
     &&
   
      s1
   
     <
   
     distance[j])

   
     35 
   
      distance[j]
   
     =
   
     s1;

   
     36 
   
      }

   
     37 
   
      }

   
     38 
   
      
   
     return
   
      sum;

   
     39 
   
     }

   
     40 
   
     
   
     int
   
      main()

   
     41 
   
     {

   
     42 
   
      
   
     int
   
      i;
   
     double
   
      x,y;

   
     43 
   
      
   
     while
   
     (scanf(
   
     "
   
     %d
   
     "
   
     ,
   
     &
   
     n)
   
     !=
   
     EOF)

   
     44 
   
      {

   
     45 
   
      
   
     for
   
     (i
   
     =
   
     1
   
     ;i
   
     <=
   
     n;i
   
     ++
   
     )

   
     46 
   
      {

   
     47 
   
      scanf(
   
     "
   
     %lf%lf
   
     "
   
     ,
   
     &
   
     x,
   
     &
   
     y);

   
     48 
   
      s[i].x
   
     =
   
     x;

   
     49 
   
      s[i].y
   
     =
   
     y;

   
     50 
   
      }

   
     51 
   
      printf(
   
     "
   
     %.2lf\n
   
     "
   
     ,prim(
   
     1
   
     ));

   
     52 
   
      }

   
     53 
   
      
   
     return
   
      
   
     0
   
     ;

   
     54 
   
     }