Building Teams

def building_teams(n,friendships):

    from collections import defaultdict,deque

    graph = defaultdict(list)
    for a,b in friendships:
        graph[a].append(b)
        graph[b].append(a)

    visited = [False] * (n+1) 
    components = []

    for i in range(1, n + 1):
        if visited[i] == False:  
            queue = deque([i])
            visited[i] = 1
            while queue:
                node = queue.popleft()
                for neighbor in graph[node]:
                    if visited[neighbor] == False:  
                        visited[neighbor] = 3 - visited[node]  
                        queue.append(neighbor)
                    elif visited[neighbor] == visited[node]:
                        return "IMPOSSIBLE"
    return " ".join(map(str, visited[1:]))

#     def dfs(node, component):
#         visited[node] = True
#         component.append(node)
#         for neighbour in graph[node]:
#             if not visited[neighbour]:
#                 dfs(neighbour, component)

#     for i in range(1, n+1):
#         if not visited[i]:
#             component = []
#             dfs(i, component)
#             components.append(component)

#     return components

# def solution(n, friendships):
#     components = building_teams(n,friendships)

#     if n==1:
#         return "IMPOSSIBLE"
    
#     group1 = []
#     group2 = []
#     for i in range(len(components)-1):
#         group1 = components[i][0]
#         group2 = components[i+1][0]
    
#     return group1


n,m = map(int, input().split())

friendships = []
for _ in range(m):
    a,b = map(int, input().split())
    friendships.append((a,b))

print(building_teams(n,friendships))
# print(solution(n,friendships))

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED