![]() | ||||
Online Judge | Problem Set | Authors | Online Contests | User |
---|---|---|---|---|
Web Board Home Page F.A.Qs Announcement | Current Contest Past Contests Scheduled Contests Award Contest |
Chessboard Time Limit:2000MS Memory Limit:65536K
Alice and Bob often play games on chessboard. One day, Alice draws a
board with size M * N. She wants Bob to use a lot of cards with size 1
* 2 to cover the board. However, she thinks it too easy to bob, so she
makes some holes on the board (as shown in the figure below). ![]() We call a grid, which doesnĄ¯t contain a hole, a normal grid. Bob has to follow the rules below: 1. Any normal grid should be covered with exactly one card. 2. One card should cover exactly 2 normal adjacent grids. Some examples are given in the figures below: ![]() A VALID solution. ![]() An invalid solution, because the hole of red color is covered with a card. ![]() An invalid solution, because there exists a grid, which is not covered. Your task is to help Bob to decide whether or not the chessboard can be covered according to the rules above. Input There are 3 integers in the first line: m, n, k (0 < m, n <= 32, 0 <= K < m * n), the number of rows, column and holes. In the next k lines, there is a pair of integers (x, y) in each line, which represents a hole in the y-th row, the x-th column. OutputIf the board can be covered, output "YES". Otherwise, output "NO". Sample Input
POJ Monthly,charlescpp |
[Submit] [Go Back] [Status] [Discuss]
All Copyright Reserved 2003-2005 Ying Fuchen,Xu Pengcheng
Any problem, Please Contact Administrator