以前的一个a*练习,搬过来凑个数……
A*算法描述见这篇博文
ruby代码:
#encoding=utf-8 MAP = [ [0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 1, 0, 0, 0, 0], [0, 0, 0, 1, 0, 0, 0, 0], [0, 0, 0, 1, 1, 0, 1, 0], [0, 0, 0, 1, 0, 0, 0, 0], [0, 0, 0, 1, 0, 0, 0, 0], [0, 0, 0, 1, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0], ] class Point attr_accessor :x attr_accessor :y attr_accessor :g attr_accessor :h attr_accessor :f attr_accessor :parent def initialize(x, y, parent) self.x = x self.y = y self.parent = parent end def to_s "#{super.to_s}, #{[self.x, self.y, self.g, self.h, self.f]}" end end $open = {} $close = {} def find(sx, sy, ex, ey) startP = Point.new(sx, sy, nil) startP.g = 0 pos = startP while (!$open[[ex, ey]]) do dealAround(pos, ex, ey) # 检查周围元素,计算f pos = getMinFPos end pos = $open[[ex, ey]] path = [] while (pos.parent) do path << [pos.x, pos.y] pos = pos.parent end path << [pos.x, pos.y] for y in 0...MAP.size for x in 0...MAP[0].size print (path.include?([x, y])) ? "☆" : (MAP[y][x] == 0 ? "□" : "■") end print "\r\n" end p path end def getMinFPos return nil if $open.size < 1 minG = $open.values[0].g minGPos = $open.values[0] $open.values.each{|pos| if minG > pos.g minG = pos.g minGPos = pos end } return minGPos end def dealAround(pos, endx, endy) # 将pos加入close列表 $close[[pos.x, pos.y]] = pos # 将pos从open列表中移出 $open.delete([pos.x, pos.y]) # 检查周围元素 [[-1, -1], [0, -1], [1, -1], [-1, 0], [1, 0], [-1, 1], [0, 1], [1, 1]].each{|posOffset| # 跳过边界 next if pos.x + posOffset[0] < 0 or pos.y + posOffset[1] < 0 or pos.x + posOffset[0] > MAP[0].size - 1 or pos.y + posOffset[1] > MAP.size - 1 # 跳过不可通行的方块 next if MAP[pos.y + posOffset[1]][pos.x + posOffset[0]] != 0 # 跳过close列表 next if $close[[pos.x + posOffset[0], pos.y + posOffset[1]]] newPos = Point.new(pos.x + posOffset[0], pos.y + posOffset[1], pos) # 计算g if posOffset[0].abs + posOffset[1].abs == 2 # 斜向 newPos.g = pos.g + 14 else newPos.g = pos.g + 10 end # 计算h newPos.h = (endx - newPos.x).abs * 10 + (endy - newPos.y).abs * 10 # 计算f newPos.f = newPos.g + newPos.h # 添加到open列表 if $open[[newPos.x, newPos.y]] # 已存在 thePos = $open[[newPos.x, newPos.y]] tempG = ((thePos.x - pos.x).abs + (thePos.y - pos.y).abs == 2) ? (pos.g + 14) : (pos.g + 10) if tempG < thePos.g # 当前节点使g更小 thePos.g = tempG thePos.f = tempG + thePos.h thePos.parent = pos # 修改父节点为当前节点 end else # 不存在 $open[[newPos.x, newPos.y]] = newPos end } end find(0, 0, 7, 7)