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;

}