一.题目要求
参考下图完成游戏地图中从起点到目标点的最短路径寻找问题。
二.设计思路
先对游戏地图做了几个设定,以矩阵来模拟游戏地图。将可行的区域位置赋值0,障碍区赋值为inf。考虑到地图大小,将起始点和终点区域赋值99。
从start点a开始向外层扩展,每扩展一层pathlen加一。list q存储当前需要扩展的点,list p 存储当前扩展层。当扩展到end点b时扩展结束,路径可规划。当q为空时,本次层扩展结束,检查p,若p非空,从p层向外扩展,若p为空,则end点b无法到达。
寻找最短路径时,从end点b开始,寻找当前点附近8个点的标记中比当前点标记小的点,直到标记为1为止。
三.程序主体
python" id="highlighter_658761">
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# -*-coding:gbk -*- from numpy import * dirs = [( 1 , 1 ),( 1 , 0 ),( 1 , - 1 ),( 0 , - 1 ),( - 1 , - 1 ),( - 1 , 0 ),( - 1 , 1 ),( 0 , 1 )] # 四邻位置:从右下角开始顺时针得到,是按坐标差得到的 def find_path(oldmap,a,b): oldmap[a[ 0 ], a[ 1 ]] = 99 oldmap[b[ 0 ], b[ 1 ]] = 99 [a,b] = oldmap.shape pathmap = oldmap.copy() q = [] #存储扩展节点 p = [] #往外一层 pathlen = 1 if a = = b: print ( 'start point is equal to end point' ) return true current = a while (true): for i in range ( 8 ): neighbor = [current[ 0 ] + dirs[i][ 0 ], current[ 1 ] + dirs[i][ 1 ]] if neighbor = = b: print ( 'the way is found' ) ######################wrong print ( '中间过程' ) print (oldmap) find_way(oldmap,pathmap,a,b,a,b) #####调用路径函数 return true if (neighbor[ 0 ]> = 0 and neighbor[ 1 ]> = 0 and neighbor[ 0 ]<a and neighbor[ 1 ]<b and oldmap[neighbor[ 0 ],neighbor[ 1 ]] = = 0 ): p.append(neighbor) oldmap[neighbor[ 0 ],neighbor[ 1 ]] = pathlen if q = = []: if p = = []: print (oldmap) ############## print ( 'no path' ) return false else : q.extend(p) p = [] pathlen + = 1 else : current = q.pop() ###################寻找最短路径 def find_way(oldmap,pathmap,a,b,a,b): currentpos = b while (oldmap[currentpos[ 0 ],currentpos[ 1 ]]! = 1 ): for i in range ( 8 ): neighborpos = [currentpos[ 0 ] + dirs[i][ 0 ], currentpos[ 1 ] + dirs[i][ 1 ]] if (neighborpos[ 0 ] > = 0 and neighborpos[ 1 ] > = 0 and neighborpos[ 0 ] < a and neighborpos[ 1 ] < b and oldmap[neighborpos[ 0 ],neighborpos[ 1 ]]! = 0 ): if oldmap[neighborpos[ 0 ],neighborpos[ 1 ]]<oldmap[currentpos[ 0 ],currentpos[ 1 ]]: pathmap[neighborpos[ 0 ],neighborpos[ 1 ]] = oldmap[neighborpos[ 0 ],neighborpos[ 1 ]] currentpos = neighborpos break print ( 'the way:' ) print (pathmap) |
四.主函数
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def main(): map = mat([[ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 ], [ 0 , 0 , 0 , 0 , inf,inf, 0 , 0 , 0 , 0 , 0 , 0 , 0 ], [ 0 , 0 , 0 , 0 , 0 ,inf, 0 , 0 , 0 , 0 , 0 , 0 , 0 ], [inf,inf,inf, 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 ], [ 0 , 0 ,inf, 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , inf], [ 0 , 0 ,inf, 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , inf], [ 0 , 0 ,inf, 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 ,inf], [ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , inf], [ 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 ],]) print ( '最初地图' ) print ( map ) print ( '**********************************' ) a = [ 5 , 0 ] # b=[5,0] b = [ 3 , 12 ] find_path( map ,a, b) if __name__ = = '__main__' : main() |
五.运行结果
六.结果分析
由中间过程对应的矩阵可知,共经历了12次向外层扩展,第12次扩展即可将目标点包含进去。最短路径如the way对应的矩阵所示,是通过一种类似梯度下降的方法得到的。
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。
原文链接:https://blog.csdn.net/weixin_41819299/article/details/80840286