题目来源:http://acm.hdu.edu.cn/showproblem.php?pid=1312
问题和上一篇博客一样,都是图的搜索问题
上一篇博客采用深度优先搜索,这次采用广度优先搜索
对于这个问题两种搜索算法都能AC,时间空间开销也差不多,实现上也差不多,就是把数据结构改一改,point类的核心算法代码改一改
1312: Red and Black
Time Limit: 2000/1000 MS(Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Problem Description
There is a rectangular room, covered withsquare tiles. Each tile is colored either red or black. A man is standing on ablack tile. From a tile, he can move to one of four adjacent tiles. But hecan't move on red tiles, he can move only on black tiles.
Write a program to count the number of black tiles which he can reach byrepeating the moves described above.
Input
The input consists of multiple data sets. Adata set starts with a line containing two positive integers W and H; W and Hare the numbers of tiles in the x- and y- directions, respectively. W and H arenot more than 20.
There are H more lines in the data set, each of which includes W characters.Each character represents the color of a tile as follows.
'.' - a black tile
'#' - a red tile
'@' - a man on a black tile(appears