洛谷1005（dp）

1.不要贪，缩小区间去dp就好。

2.预处理指数。

3.__int128可还行。

 #include <cstdio>
 #include <cctype>
 #include <cstring>
 #include <iostream>
 #include <algorithm>
 using namespace std;

 template <typename T> void read(T &x) {
     x = ;
     int s = , c = getchar();
     for (; !isdigit(c); c = getchar())
         if (c == '-')    s = -;
     for (; isdigit(c); c = getchar())
         x = x *  + c - ;
     x *= s;
 }

 template <typename T> void write(T x) {
     if (x < )    x = -x, putchar('-');
     if (x > )    write(x / );
     putchar(x %  + '');
 }

 template <typename T> void writeln(T x) {
     write(x);
     puts("");
 }

 const int maxn = ;

 __int128 f[maxn][maxn], p[maxn], num[maxn], ans;

 __int128 dp(int l, int r, int depth) {
     if (l == r)    f[l][r] = num[l] * p[depth];
     if (f[l][r] >= )    return f[l][r];
     return    f[l][r] = max(num[l] * p[depth] + dp(l + , r, depth + ), num[r] * p[depth] + dp(l, r - , depth + ));
 }

 int main() {
     int n, m;
     read(n), read(m);
     p[] = ;
     for (int i = ; i <= m; i++)
         p[i] = p[i - ] * ;
     for (int i = ; i <= n; i++) {
         for (int j = ; j <= m; j++)
             read(num[j]);
         memset(f, -, sizeof f);
         ans += dp(, m, );
     }
     writeln(ans);
     return ;
 }