hdu4597Play Game(记忆化）

链接

通化邀请赛的题 貌似不怎么难

记忆化DP 状态方程类似于2维的 只是变成了4维  每次有四种方向去搜 取最棒的

判断好边界条件

 #include <iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #include<stdlib.h>
 using namespace std;
 int p1[],p2[],sum1[],sum2[];
 int dp[][][][];
 int dfs(int i1,int j1,int i2,int j2)
 {
     if(dp[i1][j1][i2][j2]!=-)
     return dp[i1][j1][i2][j2];
     if(i1>j1&&i2>j2)
     return dp[i1][j1][i2][j2] = ;
     int d1=,d2=,d3=,d4=;
     int s1 = sum1[j1]-sum1[i1-];
     int s2 = sum2[j2]-sum2[i2-];
     if(i1<=j1)
     {
         d1 = s2+sum1[j1-]-sum1[i1-]-dfs(i1,j1-,i2,j2)+p1[j1];
         d2 = s2+sum1[j1]-sum1[i1]-dfs(i1+,j1,i2,j2)+p1[i1];
     }
     if(i2<=j2)
     {
         d3 = s1+sum2[j2-]-sum2[i2-]-dfs(i1,j1,i2,j2-)+p2[j2];
         d4 = s1+sum2[j2]-sum2[i2]-dfs(i1,j1,i2+,j2)+p2[i2];
     }
     dp[i1][j1][i2][j2] = max(max(d1,d2),max(d3,d4));
     return dp[i1][j1][i2][j2];
 }
 int main()
 {
     int i,n,t;
     scanf("%d",&t);
     while(t--)
     {
         cin>>n;
         memset(sum1,,sizeof(sum1));
         memset(sum2,,sizeof(sum2));
         memset(dp,-,sizeof(dp));
         for(i =  ; i <= n ;i++)
         {
             scanf("%d",&p1[i]);
             sum1[i] = sum1[i-]+p1[i];
         }
         for(i =  ; i<= n ; i++)
         {
             scanf("%d",&p2[i]);
             sum2[i] = sum2[i-]+p2[i];
         }
         int ans = dfs(,n,,n);
         cout<<ans<<endl;
     }
     return ;
 }