CSES - Aalto Competitive Programming 2026 - wk6 - Wed

Submission details
Task:	Fragile network
Sender:	aalto26fw_002
Submission time:	2026-10-07 17:03:07 +0300
Language:	Python3 (PyPy3)
Status:	READY
Result:	WRONG ANSWER

Test results
test	verdict	time
#1	ACCEPTED	0.04 s	details
#2	ACCEPTED	0.04 s	details
#3	ACCEPTED	0.04 s	details
#4	ACCEPTED	0.04 s	details
#5	ACCEPTED	0.04 s	details
#6	ACCEPTED	0.15 s	details
#7	ACCEPTED	0.12 s	details
#8	ACCEPTED	0.15 s	details
#9	ACCEPTED	0.12 s	details
#10	ACCEPTED	0.12 s	details
#11	ACCEPTED	0.04 s	details
#12	WRONG ANSWER	0.04 s	details
#13	WRONG ANSWER	0.04 s	details
#14	WRONG ANSWER	0.12 s	details
#15	WRONG ANSWER	0.04 s	details
#16	WRONG ANSWER	0.04 s	details
#17	WRONG ANSWER	0.04 s	details
#18	ACCEPTED	0.04 s	details
#19	ACCEPTED	0.04 s	details
#20	ACCEPTED	0.04 s	details
#21	ACCEPTED	0.04 s	details

Code

n = int(input())
graph = []
nodes = [0]*(n+1)
for i in range(n-1):
    buffer = input().split()
    a = int(buffer[0])
    b = int(buffer[1])
    nodes[a] += 1
    nodes[b] += 1

res = []
for i in range(1,n+1):
    if nodes[i] == 1:
        res.append(i)

#k = len(res)-1
k = (len(res)+1)//2
print(k)
for j in range(k):
    print(res[2*j],res[(2*j+1)%len(res)])

Test details

Test 1

Verdict: ACCEPTED

input
`10 1 5 1 7 1 8 1 3 ...` view save

correct output
`5 5 2 7 9 8 6 3 10 ...` view save

user output
`5 2 3 4 5 6 7 8 9 ...` view save

Test 2

Verdict: ACCEPTED

input
`10 4 5 3 4 2 3 9 10 ...` view save

correct output
`1 10 1` view save

user output
`1 1 10` view save

Test 3

Verdict: ACCEPTED

input
`10 1 8 1 3 3 5 5 7 ...` view save

correct output
`3 7 10 8 2 1 9` view save

user output
`3 2 7 8 9 10 2` view save

Test 4

Verdict: ACCEPTED

input
`10 1 5 3 7 2 10 3 8 ...` view save

correct output
`3 10 8 6 4 5 9` view save

user output
`3 4 5 6 8 9 10` view save

Test 5

Verdict: ACCEPTED

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

correct output
`3 8 7 10 9 1 6` view save

user output
`3 6 7 8 9 10 6` view save

Test 6

Verdict: ACCEPTED

input
`100000 1 56967 1 56618 1 42321 1 82550 ...` view save

correct output
`50000 56967 16911 56618 39942 42321 99902 82550 2538 ...` view save

user output
`50000 2 3 4 5 6 7 8 9 ...` view save

Test 7

Verdict: ACCEPTED

input
`100000 92297 92298 23511 23512 68057 68058 65434 65435 ...` view save

correct output
`1 100000 1` view save

user output
`1 1 100000` view save

Test 8

Verdict: ACCEPTED

input
`100000 17747 97512 10397 12053 679 6975 4013 14565 ...` view save

correct output
`25057 92881 76094 20353 87429 16069 96487 71186 52809 ...` view save

user output
`25057 388 577 715 785 837 1166 1220 1261 ...` view save

Test 9

Verdict: ACCEPTED

input
`100000 72941 72942 11232 11233 73464 73465 30042 30043 ...` view save

correct output
`489 16423 85168 20707 94190 36505 54940 96411 44067 ...` view save

user output
`489 1 99 667 718 884 1400 1404 1453 ...` view save

Test 10

Verdict: ACCEPTED

input
`100000 31451 31452 7473 7474 24056 24057 85181 85182 ...` view save

correct output
`51 25638 2983 87594 87371 92001 50610 46744 100000 ...` view save

user output
`51 1 140 346 1093 2983 5134 6092 6887 ...` view save

Test 11

Verdict: ACCEPTED

input
`10 1 2 1 3 3 4 3 5 ...` view save

correct output
`2 2 6 4 10` view save

user output
`2 2 4 6 10` view save

Test 12

Verdict: WRONG ANSWER

input
`7 1 2 2 3 2 4 1 5 ...` view save

correct output
`2 4 7 3 6` view save

user output
`2 3 4 6 7` view save

Test 13

Verdict: WRONG ANSWER

input
`6 1 2 1 3 1 4 4 5 ...` view save

correct output
`2 3 6 2 5` view save

user output
`2 2 3 5 6` view save

Test 14

Verdict: WRONG ANSWER

input
`65538 1 2 1 3 1 4 3 5 ...` view save

correct output
`16385 34 36 40 42 35 41 48 50 ...` view save

user output
`16385 2 4 33 34 35 36 39 40 ...` view save

Test 15

Verdict: WRONG ANSWER

input
`11 1 2 1 3 2 4 2 5 ...` view save

correct output
`2 9 11 8 10` view save

user output
`2 8 9 10 11` view save

Test 16

Verdict: WRONG ANSWER

input
`7 1 2 1 3 2 4 2 5 ...` view save

correct output
`2 5 7 4 6` view save

user output
`2 4 5 6 7` view save

Test 17

Verdict: WRONG ANSWER

input
`7 1 2 1 3 2 4 2 5 ...` view save

correct output
`2 5 7 4 6` view save

user output
`2 4 5 6 7` view save

Test 18

Verdict: ACCEPTED

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

correct output
`3 8 7 10 9 1 6` view save

user output
`3 6 7 8 9 10 6` view save

Test 19

Verdict: ACCEPTED

input
`7 1 2 1 5 2 3 2 6 ...` view save

correct output
`2 6 7 3 4` view save

user output
`2 3 4 6 7` view save

Test 20

Verdict: ACCEPTED

input
`8 1 2 1 3 2 4 2 5 ...` view save

correct output
`3 4 7 6 8 1 5` view save

user output
`3 4 5 6 7 8 4` view save

Test 21

Verdict: ACCEPTED

input
`10 2 1 3 1 4 2 5 4 ...` view save

correct output
`3 9 8 6 10 3 7` view save

user output
`3 3 6 7 8 9 10` view save

Aalto Competitive Programming 2026 - wk6 - Wed

Fragile network

Code

Test details

Test 1

Test 2

Test 3

Test 4

Test 5

Test 6

Test 7

Test 8

Test 9

Test 10

Test 11

Test 12

Test 13

Test 14

Test 15

Test 16

Test 17

Test 18

Test 19

Test 20

Test 21

Tasks

Submissions (aalto26fw_002)