思路：

简单的区间dp。

实现：

1 #include 
     
       2 using namespace std; 3 const int MAXN = 5005; 4 int a[MAXN][MAXN]; 5 int main() 6 { 7     int n, q, l, r; 8     while (cin >> n) 9     {10         memset(a, 0, sizeof a);11         for (int i = 1; i <= n; i++) cin >> a[i][i];12         for (int i = 2; i <= n; i++)13         {14             for (int j = 1; j <= n - i + 1; j++)15             {16                 a[j][j + i - 1] = a[j][j + i - 2] ^ a[j + 1][j + i - 1];17             }18         }19         for (int i = 2; i <= n; i++)20         {21             for (int j = 1; j <= n - i + 1; j++)22             {23                 a[j][j + i - 1] = max(a[j][j + i - 1], max(a[j][j + i - 2], a[j + 1][j + i - 1]));24             }25         }26         cin >> q;27         while (q--)28         {29             cin >> l >> r;30             cout << a[l][r] << endl;31         }32     }33     return 0;34 }