UVA - 10891 Game of Sum(记忆化搜索 区间dp)

 

 

#include<cstdio>
#include<cstring>
#include<cmath>
#include<iostream>
#include<algorithm>
using namespace std;
int a[100+10];
int dp[120][120];
int sum[120];
int vis[120][120];
int dfs(int f,int t)
{
   int i,j,k;
   if(vis[f][t]==1) return dp[f][t];
   vis[f][t]=1;

   int minn=0;
   for(i=f;i<t;i++)
   {
     minn=min(minn,dfs(f,i));
   }
   for(i=f+1;i<=t;i++)
   {
       minn=min(minn,dfs(i,t));
   }
   dp[f][t]=sum[t]-sum[f-1]-minn;
   return dp[f][t];
}
int main()
{
   int n;
   int i,j,k;
   while(scanf("%d",&n),n)
   {
      sum[0]=0;
      memset(vis,0,sizeof(vis));
      for(i=1;i<=n;i++)
      {
          scanf("%d",&a[i]);
          sum[i]=sum[i-1]+a[i];
      }
      dfs(1,n);
      printf("%d\n",dp[1][n]-(sum[n]-dp[1][n]));
   }
   return 0;
}