sgu250：Constructive Plan

题目大意：

给出一个n∗ m的01矩阵，0表示不能放，1表示能放，在其中放入三个矩形，要求满足如下条件：

1.每个矩形面积大于0。

2.这些矩形必须是一个联通块，矩形之间不能重叠。

3.矩形的左边界在同一条线上。

4.中间矩形的横向长度小于两边矩形的横向长度。

求出最大的三个矩形的总面积，无解输出− 1。-250. Constructive Plan



time limit per test: 0.25 sec.

memory limit per test: 65536 KB

input: standard

output: standard







Oh, no!　- Petya said, walking around his recently bought ground plot. Petya wants to build a new house on it. According to Petya s building project the house should look　above like　C　character.

There are many trees growing on Petya s plot. But everyone who cuts down a tree in Petya s country is sent to cut down trees for the rest of his life. So first of all Petya has to choose a place for building the house without cutting any tree.

He is feeling that he is not able to find the solution on his own, so he decided to ask you to help him.

The task is simplified a little by the fact that Petya s plot has a rectangular shape of size N*M, divided into 1*1 square cells. For each cell it is known whether there are any trees growing there. House can t occupy cells where trees grow.

Fortunately Petya could explain how his house must look　above.

1) H