poj1157

简单题

View Code

   
     

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

    
      using
    
       
    
      namespace
    
       std;


    
      #define
    
       maxn 105
    
      


    
      int
    
       n, m;

    
      int
    
       v[maxn][maxn], f[maxn][maxn];


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

    
       scanf(
    
      "
    
      %d%d
    
      "
    
      , 
    
      &
    
      n, 
    
      &
    
      m);
 
    
      for
    
       (
    
      int
    
       i 
    
      =
    
       
    
      1
    
      ; i 
    
      <=
    
       n; i
    
      ++
    
      )
 
    
      for
    
       (
    
      int
    
       j 
    
      =
    
       
    
      1
    
      ; j 
    
      <=
    
       m; j
    
      ++
    
      )
 scanf(
    
      "
    
      %d
    
      "
    
      , 
    
      &
    
      v[i][j]);
 f[
    
      1
    
      ][
    
      1
    
      ] 
    
      =
    
       v[
    
      1
    
      ][
    
      1
    
      ];
 
    
      for
    
       (
    
      int
    
       i 
    
      =
    
       
    
      2
    
      ; i 
    
      <=
    
       m; i
    
      ++
    
      )
 f[
    
      1
    
      ][i] 
    
      =
    
       max(v[
    
      1
    
      ][i], f[
    
      1
    
      ][i 
    
      -
    
       
    
      1
    
      ]);
 
    
      for
    
       (
    
      int
    
       i 
    
      =
    
       
    
      2
    
      ; i 
    
      <=
    
       n; i
    
      ++
    
      )
 {
 f[i][i] 
    
      =
    
       f[i 
    
      -
    
       
    
      1
    
      ][i 
    
      -
    
       
    
      1
    
      ] 
    
      +
    
       v[i][i];
 
    
      for
    
       (
    
      int
    
       j 
    
      =
    
       i 
    
      +
    
       
    
      1
    
      ; j 
    
      <=
    
       m; j
    
      ++
    
      )
 f[i][j] 
    
      =
    
       max(f[i 
    
      -
    
       
    
      1
    
      ][j 
    
      -
    
       
    
      1
    
      ] 
    
      +
    
       v[i][j], f[i][j 
    
      -
    
       
    
      1
    
      ]);
 }
 printf(
    
      "
    
      %d\n
    
      "
    
      , f[n][m]);
 
    
      return
    
       
    
      0
    
      ;
}