BZOJ4007 [JLOI2015]战争调度

根本想不出来。。。

原来还是暴力出奇迹啊QAQ

无限ymymym中

 /**************************************************************
     Problem: 4007
     User: rausen
     Language: C++
     Result: Accepted
     Time:240 ms
     Memory:13216 kb
 ****************************************************************/

 #include <cstdio>
 #include <cstring>
 #include <algorithm>

 using namespace std;
 const int N = ( << ) + ;

 int n, m, ans;
 int a[N][N], b[N][N], f[N][N];
 int now[N];

 inline int read();

 #define ls p << 1
 #define rs p << 1 | 1
 void dfs(int p, int sz) {
     int i, j, mnl, mxl, tot;
     if (sz == ) {
         f[p][] = f[p][] = ;
         for (i = p >> ; i; i >>= )
             if (now[i] == ) f[p][] += a[p][i];
             else f[p][] += b[p][i];
         return;
     }
     tot = min(sz, m);
     memset(f[p], , sizeof(f[][]) * (tot + ));
     now[p] = ;
     dfs(ls, sz >> ), dfs(rs, sz >> );
     for (i = ; i <= tot; ++i) {
         mnl = max(i - (sz >> ), ), mxl = min(sz >> , i);
         for (j = mnl; j <= mxl; ++j)
             f[p][i] = max(f[p][i], f[ls][j] + f[rs][i - j]);
     }

     now[p] = ;
     dfs(ls, sz >> ), dfs(rs, sz >> );
     for (i = ; i <= tot; ++i) {
         mnl = max(i - (sz >> ), ), mxl = min(sz >> , i);
         for (j = mnl; j <= mxl; ++j)
             f[p][i] = max(f[p][i], f[ls][j] + f[rs][i - j]);
     }
 }
 #undef ls
 #undef rs

 int main() {
     int i, j;
     n = read(), m = read();
     for (i =  << n - ; i <  << n; ++i)
         for (j = i >> ; j; j >>= )
             a[i][j] = read();
     for (i =  << n - ; i <  << n; ++i)
         for (j = i >> ; j; j >>= )
             b[i][j] = read();
     dfs(,  << n - );
     for (ans = i = ; i <= m; ++i)
         ans = max(ans, f[][i]);
     printf("%d\n", ans);
     return ;
 }

 inline int read() {
     static int x;
     static char ch;
     x = , ch = getchar();
     while (ch < '' || '' < ch)
         ch = getchar();
     while ('' <= ch && ch <= '') {
         x = x *  + ch - '';
         ch = getchar();
     }
     return x;
 }