poj3176

简单题

View Code

   
     

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

    
      using
    
       
    
      namespace
    
       std;


    
      #define
    
       maxn 400
    
      


    
      int
    
       n, ball[maxn][maxn], f[maxn][maxn];


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

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