Sun Yat-sen University Programming Contest

Problem A

Solved by Kilo_5723. 03:48:17 (-1)

Problem B

Solved by Kilo_5723. 00:17:23 (-2)

Problem C

Unsolved.

Problem D

Solved by Xiejiadong. 01:49:36 (-5)

题意：给出一些矩形覆盖平面，询问一个矩形区域，问是否已经被覆盖。

题解：二维平面差分。对于矩形\((a,b,c,d)\)，在位置\((a,b)\; +1\)、\((a,d+1)\; -1\)、\((c+1,b)\; -1\)、\((c+1,d+1)\; +1\)，进行一起前缀和，就能得到所有矩阵位置被覆盖的次数。

对于所有满足\(\ge 1\)的位置，即已经被覆盖的位置，改成\(1\)，其余为\(0\)，再进行一次前缀和即可支持子矩阵和查询。

对于每一个询问，只需要询问矩阵面积和子矩阵的面积相等即可。

Problem E

Unsolved.

Problem F

Unsolved.

Problem G

Unsolved.

Problem H

Unsolved.

Problem I

Unsolved.

Problem J

Unsolved.

Problem K

Unsolved.