Get Relations

一群人的关系，给出2个人 输出所有可能关系，用Map建有向图，dfs遍历有向图。感觉多条路径时候bfs不能做。

def getRelations(arr,a,b):
    mm = {}
    for x,r,y in arr:
        if x not in mm:
            mm[x] = [[y,r]]
        else:
            mm[x].append([y,r])
    seen = set()
    res = []
    def dfs(x,path):
        if x == b:
            res.append(path)
            return
        if x in mm:
            for y,r in mm.get(x):
                if y not in seen:
                    dfs(y,path + [r,y])

    dfs(a,[a])
    print(res)
getRelations([["br","bro","lis"],
              ["br","son","hom"],
              ["lis","dau","hom"],
              ["mar","wife","hom"]],"br","hom")