【NOIP考前题目回顾】Luogu P1005

思路

代码

#include <cstdio>
#include <cstring>
#include <iostream>

std::ostream& operator<<(std::ostream &dest, const __int128_t value) // 因为C++并没有给__int128_t重载流输入输出，所以cout需要我们自己写。
{
std::ostream::sentry S(dest);
if (S)
{
__uint128_t tmp = value < 0 ? -value : value;
char buffer[129];
char* d = buffer + 129;
char* d2 = d;
do
{
--d;
*d = "0123456789"[tmp % 10];
tmp /= 10;
} while (tmp != 0);
if (value < 0)
{
--d;
*d = '-';
}
int len = d2 - d;
if (dest.rdbuf()->sputn(d, len) != len)
dest.setstate(std::ios_base::badbit);
}
<
c413
span class="hljs-keyword">return dest;
}

typedef __int128_t lll;

int n,m;
lll ans=0;
int a[100]={0};
lll f[100][100];
lll p[100]={1};
lll dp()
{
memset(f, 0, sizeof f);
for (int i = 1; i <= m; i++)
for (int j = m; j >= i; j--)
f[i][j] = std::max(f[i - 1][j] + p[m - j + i - 1] * a[i - 1]  ,
f[i][j + 1] + p[m - j + i - 1] * a[j + 1]);
lll maxn = -1;
for (int i = 1; i <= m; i++)
maxn = std::max(maxn, f[i][i] + a[i] * p[m]);
return maxn;
}
int main()
{
for (int i = 1; i <= 90; i++)
p[i] = p[i - 1] << 1;
scanf("%d%d", &n, &m);
for (int i=1;i<=n;i++)
{
for (int j = 1; j <= m; j++)
scanf("%d", a + j);
ans += dp();
}
if (ans == 0)
puts("0");
else
std::cout << ans << std::endl;
#ifdef __EDWARD_EDIT
std::cin.get();
std::cin.get();
#endif
return 0;
}