PAT(Advanced Level) Practice（with python）——1003 Emergency

Code

N,M,C1,C2 = map(int,input().split())
N_list = list(map(int,input().split()))
graph = [[-1 for i in range(N)]for j in range(N)]
for i in range(M):
    c1,c2,team = map(int,input().split())
    graph[c1][c2] = team
    graph[c2][c1] = team# 无向图

min_paths = 0
max_teams = 0
visit = [0 for i in range(N)]
min_distance = float("inf")

def dfs(Start,End,road_leng,teams):
    global min_paths,max_teams,visit,min_distance
    if road_leng > min_distance:
        #  没必要走下去了
        return
    else:
        if Start==End:
            #  到达终点
            if road_leng==min_distance:
                # 之前有最短路了
                min_paths += 1
                min_distance = road_leng
                if max_teams<teams:
                    max_teams = teams
            else:
                min_paths = 1
                max_teams = teams
                min_distance = road_leng
        else:
            # 没达到终点
            for k in range(N):
                if graph[Start][k] != -1 and visit[k]==0:
                    visit[k] = 1
                    dfs(k,End,road_leng+graph[Start][k],teams+N_list[k])
                    visit[k] = 0

    
visit[C1] = 1
dfs(C1,C2,0,N_list[C1])
print(min_paths, max_teams)