poj2479

与poj2593相同

View Code

   
     

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

    
      using
    
       
    
      namespace
    
       std;


    
      #define
    
       maxn 100003
    
      


    
      int
    
       f[maxn], fleft[maxn], fright[maxn];

    
      int
    
       n;


    
      void
    
       input()
{
 
    
      for
    
       (
    
      int
    
       i 
    
      =
    
       
    
      0
    
      ; i 
    
      <
    
       n; i
    
      ++
    
      )
 scanf(
    
      "
    
      %d
    
      "
    
      , 
    
      &
    
      f[i]);
}


    
      void
    
       work1()
{
 fleft[
    
      0
    
      ] 
    
      =
    
      f[
    
      0
    
      ];
 
    
      for
    
       (
    
      int
    
       i 
    
      =
    
       
    
      1
    
      ; i 
    
      <
    
       n; i
    
      ++
    
      )
 
    
      if
    
       (f[i] 
    
      >
    
       fleft[i 
    
      -
    
       
    
      1
    
      ] 
    
      +
    
       f[i])
 fleft[i] 
    
      =
    
       f[i];
 
    
      else
    
      
 fleft[i] 
    
      =
    
       fleft[i 
    
      -
    
       
    
      1
    
      ] 
    
      +
    
       f[i];
 
    
      for
    
       (
    
      int
    
       i 
    
      =
    
       
    
      1
    
      ; i 
    
      <
    
       n; i
    
      ++
    
      )
 fleft[i] 
    
      =
    
       max(fleft[i 
    
      -
    
       
    
      1
    
      ], fleft[i]);
}


    
      void
    
       work2()
{
 fright[n 
    
      -
    
       
    
      1
    
      ] 
    
      =
    
      f[n 
    
      -
    
       
    
      1
    
      ];
 
    
      for
    
       (
    
      int
    
       i 
    
      =
    
       n 
    
      -
    
       
    
      2
    
      ; i 
    
      >=
    
       
    
      0
    
      ; i
    
      --
    
      )
 
    
      if
    
       (f[i] 
    
      >
    
       fright[i 
    
      +
    
       
    
      1
    
      ] 
    
      +
    
       f[i])
 fright[i] 
    
      =
    
       f[i];
 
    
      else
    
      
 fright[i] 
    
      =
    
       fright[i 
    
      +
    
       
    
      1
    
      ] 
    
      +
    
       f[i];
 
    
      for
    
       (
    
      int
    
       i 
    
      =
    
       n 
    
      -
    
       
    
      2
    
      ; i 
    
      >=
    
       
    
      0
    
      ; i
    
      --
    
      )
 fright[i] 
    
      =
    
       max(fright[i 
    
      +
    
       
    
      1
    
      ], fright[i]);
}


    
      void
    
       work3()
{
 
    
      int
    
       ans 
    
      =
    
       
    
      -
    
      1000000000
    
      ;

 
    
      for
    
       (
    
      int
    
       i 
    
      =
    
       
    
      0
    
      ; i 
    
      <
    
       n 
    
      -
    
       
    
      1
    
      ; i
    
      ++
    
      )
 ans 
    
      =
    
       max(ans, fleft[i] 
    
      +
    
       fright[i 
    
      +
    
       
    
      1
    
      ]);
 printf(
    
      "
    
      %d\n
    
      "
    
      , ans);
}


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

    
       
    
      int
    
       t;
 scanf(
    
      "
    
      %d
    
      "
    
      , 
    
      &
    
      t);
 
    
      while
    
       (t
    
      --
    
      )
 {
 scanf(
    
      "
    
      %d
    
      "
    
      , 
    
      &
    
      n);
 input();
 work1();
 work2();
 work3();
 }
 
    
      return
    
       
    
      0
    
      ;
}