CSES - Aalto Competitive Programming 2026 - wk2 - Mon

Submission details
Task:	Building Teams
Sender:	aalto26bm_021
Submission time:	2026-09-07 17:12:37 +0300
Language:	Python3 (PyPy3)
Status:	READY
Result:	WRONG ANSWER

Test results
test	verdict	time
#1	WRONG ANSWER	0.04 s	details
#2	WRONG ANSWER	0.04 s	details
#3	WRONG ANSWER	0.04 s	details
#4	WRONG ANSWER	0.04 s	details
#5	WRONG ANSWER	0.04 s	details
#6	OUTPUT LIMIT EXCEEDED	0.00 s	details
#7	OUTPUT LIMIT EXCEEDED	0.00 s	details
#8	OUTPUT LIMIT EXCEEDED	0.00 s	details
#9	OUTPUT LIMIT EXCEEDED	0.00 s	details
#10	OUTPUT LIMIT EXCEEDED	0.00 s	details
#11	RUNTIME ERROR	0.09 s	details
#12	RUNTIME ERROR	0.09 s	details

Code

n,m = [int(x) for x in input().split()]
mapping = list(range(0,n+1)) #zero ignored
IMPOSSIBLE = False
def sign(a:int): 
    return a//abs(a)
def moreToPopagate(a:int):
    global mapping
    global IMPOSSIBLE
    v = mapping[abs(a)]
    if -v == abs(a):
        IMPOSSIBLE = True
        return False
    return mapping[abs(a)] != mapping[abs(v)]*sign(v)
def propagate(a: int):
    global mapping
    global IMPOSSIBLE
    v = mapping[abs(a)]
    if -v == abs(a):
        IMPOSSIBLE = True
        print(1)
        return
    mapping[abs(a)] = mapping[abs(v)]*sign(v)
    if moreToPopagate(a):
        propagate(a)

def isLowest(a: int):
    return abs(mapping[abs(a)]) == abs(a)
def doMapping(a: int, b:int):
    global mapping
    global IMPOSSIBLE
    if IMPOSSIBLE: return
    if (-a==b): IMPOSSIBLE = True
    if (abs(a) > abs(b)): return doMapping(b,a)
    if (b != abs(b)): return doMapping(-a,-b)
    propagate(a)
    propagate(b)
    if (not isLowest(a) or not isLowest(b)): return doMapping(sign(a)*mapping[abs(a)],sign(b)*mapping[abs(b)])
    assert(mapping[abs(a)])
    mapping[b] = -a
    print(mapping)

i = m
while i != 0: 
    a,b = input().split()
    doMapping(int(a),int(b))
    i -= 1

for i in range(1,n+1):
    while moreToPopagate(i): 
        propagate(i)
        
if IMPOSSIBLE:
    print("IMPOSSIBLE")
else:
    toPrint = []
    for i in range(1,n+1):
        if mapping[i] > 0: 
            toPrint.append(1)
        else:
            toPrint.append(2)
    print(toPrint)

Test details

Test 1

Verdict: WRONG ANSWER

input
`10 20 3 4 8 10 3 7 1 8 ...` view save

correct output
`1 1 1 2 2 1 2 2 2 1` view save

user output
`[0, 1, 2, 3, -3, 5, 6, 7, 8, 9...` view save

Test 2

Verdict: WRONG ANSWER

input
`10 20 1 3 8 10 2 4 6 8 ...` view save

correct output
`1 1 2 2 1 1 1 2 1 1` view save

user output
`[0, 1, 2, -1, 4, 5, 6, 7, 8, 9...` view save

Test 3

Verdict: WRONG ANSWER

input
`10 20 7 10 3 10 9 10 2 10 ...` view save

correct output
`1 2 2 1 1 1 2 1 2 1` view save

user output
`[0, 1, 2, 3, 4, 5, 6, 7, 8, 9,...` view save

Test 4

Verdict: WRONG ANSWER

input
`10 20 2 4 2 10 7 10 4 6 ...` view save

correct output
`1 2 1 1 2 2 2 1 2 1` view save

user output
`[0, 1, 2, 3, -2, 5, 6, 7, 8, 9...` view save

Test 5

Verdict: WRONG ANSWER

input
`10 20 3 5 8 10 9 10 1 8 ...` view save

correct output
`IMPOSSIBLE` view save

user output
`[0, 1, 2, 3, 4, -3, 6, 7, 8, 9...` view save