Codeforces731E Funny Game

dp[i][0]表示从i出发，轮到先手走的最优值。

dp[i][1]表示从i出发，轮到后手走的最优值。

dp[i][0]=max(dp[j][1]+sum[j])

dp[i][1]=min(dp[j][0]-sum[j])

倒着推就好了。

 #include <bits/stdc++.h>
 using namespace std;

 int a[];
 int dp[][];
 int sum[];

 int main()
 {
     int n;
     scanf("%d", &n);
     for (int i = ; i <= n; i++)
         scanf("%d", a + i), sum[i] = sum[i - ] + a[i];
     int houShouMax = sum[n], xianShouMin = -sum[n];
     for (int i = n - ; i >= ; i--)
     {
         dp[i][] = houShouMax;
         dp[i][] = xianShouMin;
         houShouMax = max(houShouMax, dp[i][] + sum[i]);
         xianShouMin = min(xianShouMin, dp[i][] - sum[i]);
     }
     printf("%d", dp[][]);
     return ;
 }