Road network

import queue

#Read input
n, m = [int(i) for i in input().split()]

#Read edge inputs and initialize edges
connections = {i: [] for i in range(1,n+1)}
#print(connections)

for i in range(m):
    a,b = [int(i) for i in input().split()]
    #print(a,b)
    connections[a].append(b)
    connections[b].append(a)

#Search with Breadth-first-search
def bfs(start):

    #Initialize a queue for BFS with starting vertex
    left = queue.Queue()
    left.put(start)

    found = [False] * n
    #print(found)
    found[start-1] = True
    num_found = 1

    #Continue until no unvisited neighbors left
    while not left.empty():
        
        #Take first vertex from the "waiting line"
        current = left.get()

        #print("CURRENT:  {}, found: {}".format(current, found))
        
        #Go trough every neighbor
        for neighbor in connections[current]:
            #If was not found
            if not found[neighbor-1]:
                left.put(neighbor) #Add neighbor to visit-list
                found[neighbor-1] = True #Mark as found
                num_found += 1

    if num_found == n:
        return "YES"
    else:
        for i in range(n):
            if not found[n-1]:
                return "NO\n{} {}".format(start, n)
    
#Print answer:
print(bfs(1))

Test 1

Verdict: WRONG ANSWER

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: ACCEPTED

Test 6

Verdict: TIME LIMIT EXCEEDED

Test 7

Verdict: TIME LIMIT EXCEEDED

Test 8

Verdict: TIME LIMIT EXCEEDED

Test 9

Verdict: TIME LIMIT EXCEEDED

Test 10

Verdict: TIME LIMIT EXCEEDED

Test 11

Verdict: WRONG ANSWER