Dijkstra python version

dijkstra.py

class Solution:
    def dijkstra(self, K, N, delay, graph, TIMEOUT):
        Q = set(range(N))                
        delay[K-1] = 0
        hp = []
        heapq.heappush(hp, (0, K-1))
        while len(hp) > 0:
            _, u = heapq.heappop(hp) 
            for v, w in graph[u].items():
                if delay[u] + w < delay[v]:
                    delay[v] = delay[u] + w
                    heapq.heappush(hp, (delay[v], v))
        d = max(delay)
        if d == TIMEOUT:
            d = -1
        return d
     
    def networkDelayTime(self, times, N, K):
        """
        :type times: List[List[int]]
        :type N: int
        :type K: int
        :rtype: int
        """
        graph = {}
        delay = []
        pre = []
        TIME_OUT = 100000
        for it in range(N):
            graph[it] = {}           
            delay.append(TIME_OUT)
            pre.append(-1)
        for list_it in times:        
            u, v, w = list_it
            graph[u-1][v-1] = w 
        return self.dijkstra(K, N, delay, graph, TIME_OUT)