poj3628

dfs

View Code

   
     

    
      #include 
    
      <
    
      iostream
    
      >
    
      
#include 
    
      <
    
      cstdio
    
      >
    
      
#include 
    
      <
    
      cstdlib
    
      >
    
      
#include 
    
      <
    
      cstring
    
      >
    
      

    
      using
    
       
    
      namespace
    
       std;


    
      #define
    
       maxn 25
    
      


    
      int
    
       n, m;

    
      int
    
       f[maxn], s[maxn];

    
      int
    
       ans;


    
      void
    
       dfs(
    
      int
    
       cow, 
    
      int
    
       sum)
{
 
    
      if
    
       (ans 
    
      ==
    
       
    
      0
    
      )
 
    
      return
    
      ;
 
    
      if
    
       (s[cow] 
    
      +
    
       sum 
    
      <
    
       m)
 
    
      return
    
      ;
 
    
      if
    
       (sum 
    
      >=
    
       m)
 {
 ans 
    
      =
    
       min(ans, sum 
    
      -
    
       m);
 
    
      return
    
      ;
 }
 
    
      if
    
       (cow 
    
      ==
    
       n)
 
    
      return
    
      ;
 dfs(cow 
    
      +
    
       
    
      1
    
      , sum);
 dfs(cow 
    
      +
    
       
    
      1
    
      , sum 
    
      +
    
       f[cow]);
}


    
      int
    
       main()
{
 
    
      //
    
      freopen("t.txt", "r", stdin);
    
      

    
       scanf(
    
      "
    
      %d%d
    
      "
    
      , 
    
      &
    
      n, 
    
      &
    
      m);
 
    
      for
    
       (
    
      int
    
       i 
    
      =
    
       
    
      0
    
      ; i 
    
      <
    
       n; i
    
      ++
    
      )
 scanf(
    
      "
    
      %d
    
      "
    
      , 
    
      &
    
      f[i]);
 s[n] 
    
      =
    
       
    
      0
    
      ;
 
    
      for
    
       (
    
      int
    
       i 
    
      =
    
       n 
    
      -
    
       
    
      1
    
      ; i 
    
      >=
    
       
    
      0
    
      ; i
    
      --
    
      )
 s[i] 
    
      =
    
       s[i 
    
      +
    
       
    
      1
    
      ] 
    
      +
    
       f[i];
 ans 
    
      =
    
       
    
      0x3f3f3f3f
    
      ;
 dfs(
    
      0
    
      , 
    
      0
    
      );
 printf(
    
      "
    
      %d\n
    
      "
    
      , ans);
 
    
      return
    
       
    
      0
    
      ;
}