dij

import heapq
def dij(graph,start):
    dist = {
        0: float('inf'),
        1: float('inf'),
        2: float('inf'),
        3: float('inf')
    }
    dist[start]=0
    heap=[]
    heapq.heappush(heap,(0,start))
    while heap:
        curr,node=heapq.heappop(heap)
        for neighbour,weight in graph[node]:
            new_dist=curr+weight
            if new_dist<dist[neighbour]:
                dist[neighbour]=new_dist
                heapq.heappush(heap,(new_dist,neighbour))
    return dist
        
graph = {
    0: [(1, 1), (2, 4)],      # Node 0 → Node 1 (weight 1), Node 2 (weight 4)
    1: [(0, 1), (2, 2), (3, 5)],  # Node 1 → Node 0, Node 2, Node 3
    2: [(0, 4), (1, 2), (3, 1)],
    3: [(1, 5), (2, 1)] 
    }
for i in range(4):
    shortest_distances = dij(graph, i)
    print(shortest_distances)