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。
1 #include <cstdio> 2 #include <cctype> 3 #include <cstring> 4 #include <iostream> 5 #include <algorithm> 6 using namespace std; 7 8 template <typename T> void read(T &x) { 9 x = 0; 10 int s = 1, c = getchar(); 11 for (; !isdigit(c); c = getchar()) 12 if (c == '-') s = -1; 13 for (; isdigit(c); c = getchar()) 14 x = x * 10 + c - 48; 15 x *= s; 16 } 17 18 template <typename T> void write(T x) { 19 if (x < 0) x = -x, putchar('-'); 20 if (x > 9) write(x / 10); 21 putchar(x % 10 + '0'); 22 } 23 24 template <typename T> void writeln(T x) { 25 write(x); 26 puts(""); 27 } 28 29 const int maxn = 81; 30 31 __int128 f[maxn][maxn], p[maxn], num[maxn], ans; 32 33 __int128 dp(int l, int r, int depth) { 34 if (l == r) f[l][r] = num[l] * p[depth]; 35 if (f[l][r] >= 0) return f[l][r]; 36 return f[l][r] = max(num[l] * p[depth] + dp(l + 1, r, depth + 1), num[r] * p[depth] + dp(l, r - 1, depth + 1)); 37 } 38 39 int main() { 40 int n, m; 41 read(n), read(m); 42 p[0] = 1; 43 for (int i = 1; i <= m; i++) 44 p[i] = p[i - 1] * 2; 45 for (int i = 1; i <= n; i++) { 46 for (int j = 1; j <= m; j++) 47 read(num[j]); 48 memset(f, -1, sizeof f); 49 ans += dp(1, m, 1); 50 } 51 writeln(ans); 52 return 0; 53 }
