【HDOJ】2888 Check Corners

二维RMQ。

 /* 2888 */
 #include <iostream>
 #include <algorithm>
 #include <cstdio>
 #include <cstring>
 #include <cstdlib>
 using namespace std;

 #define MAXN 305
 #define MAXM 9

 int bit[MAXN];
 int dp[MAXN][MAXN][MAXM][MAXM];
 int n, m;

 void RMQ_init() {
     int i, j, k;
     int ii, jj;

     for (i=; i<=n; ++i)
         for (j=; j<=m; ++j)
             scanf("%d", &dp[i][j][][]);
     for (ii=; (<<ii)<=n; ++ii) {
         for (jj=; (<<jj)<=m; ++jj) {
             if (ii== && jj==)
                 continue;
             for (i=; i+(<<ii)-<=n; ++i) {
                 for (j=; j+(<<jj)-<=m; ++j) {
                     if (ii)
                         dp[i][j][ii][jj] = max(dp[i][j][ii-][jj], dp[i+(<<(ii-))][j][ii-][jj]);
                     else
                         dp[i][j][ii][jj] = max(dp[i][j][ii][jj-], dp[i][j+(<<(jj-))][ii][jj-]);
                 }
             }
         }
     }
 }

 int RMQ(int lx, int ly, int rx, int ry) {
     int kx = , ky = ;

     while ((<<(kx+)) <= (rx-lx+))
         ++kx;
     while ((<<(ky+)) <= (ry-ly+))
         ++ky;
     return max(
         max(dp[lx][ly][kx][ky], dp[rx-(<<kx)+][ly][kx][ky]),
         max(dp[lx][ry-(<<ky)+][kx][ky], dp[rx-(<<kx)+][ry-(<<ky)+][kx][ky])
     );
 }

 int main() {
     int i, j, k;
     int r1, c1, r2, c2;

     #ifndef ONLINE_JUDGE
         freopen("data.in", "r", stdin);
         freopen("data.out", "w", stdout);
     #endif

     while (scanf("%d %d", &n, &m)!=EOF)  {
         RMQ_init();
         scanf("%d", &j);
         while (j--) {
             scanf("%d %d %d %d", &r1, &c1, &r2, &c2);
             if (r1 > r2) swap(r1, r2);
             if (c1 > c2) swap(c1, c2);
             k = RMQ(r1, c1, r2, c2);
             if (k==dp[r1][c1][][] || k==dp[r1][c2][][] || k==dp[r2][c1][][] || k==dp[r2][c2][][])
                 printf("%d yes\n", k);
             else
                 printf("%d no\n", k);
         }
     }

     return ;
 }