CSES - Aalto Competitive Programming 2025 - wk6 - Wed

Submission details
Task:	Fragile network
Sender:	aalto25f_004
Submission time:	2025-10-08 17:36:39 +0300
Language:	Python3 (PyPy3)
Status:	READY
Result:	RUNTIME ERROR

Test results
test	verdict	time
#1	ACCEPTED	0.04 s	details
#2	RUNTIME ERROR	0.07 s	details
#3	ACCEPTED	0.04 s	details
#4	RUNTIME ERROR	0.06 s	details
#5	ACCEPTED	0.04 s	details
#6	ACCEPTED	0.31 s	details
#7	RUNTIME ERROR	0.29 s	details
#8	WRONG ANSWER	0.34 s	details
#9	ACCEPTED	0.27 s	details
#10	ACCEPTED	0.27 s	details
#11	RUNTIME ERROR	0.07 s	details
#12	RUNTIME ERROR	0.07 s	details
#13	RUNTIME ERROR	0.06 s	details
#14	RUNTIME ERROR	0.20 s	details
#15	RUNTIME ERROR	0.07 s	details
#16	RUNTIME ERROR	0.07 s	details
#17	RUNTIME ERROR	0.06 s	details
#18	ACCEPTED	0.04 s	details
#19	RUNTIME ERROR	0.07 s	details
#20	ACCEPTED	0.04 s	details
#21	RUNTIME ERROR	0.07 s	details

Code

n = int(input())

matrice = {i:0 for i in range(n)}
for _ in range(n-1):
    a, b = [int(x) for x in input().split()]
    matrice[a-1] += 1
    matrice[b-1] += 1

less_than_one = []
for i in range(n):
    if matrice[i] < 2:
        less_than_one.append(i)

print((len(less_than_one) + 1)//2)
while len(less_than_one) > 1:
    actual_node = less_than_one.pop()
    next_node = less_than_one.pop()
    print(actual_node+1, end=' ')
    print(next_node + 1)
other_node = n - (less_than_one[0]+1)
print(less_than_one[0]+1, end=' ')
print(other_node + 1)

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 10 9 8 7 6 5 4 3 ...` view save

Test 2

Verdict: RUNTIME ERROR

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

correct output
`1 10 1` view save

user output
`1 10 1` view save

Error:

Traceback (most recent call last):
  File "input/code.py", line 20, in <module>
    other_node = n - (less_than_one[0]+1)
IndexError: list index out of range

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 10 9 8 7 2 9` view save

Test 4

Verdict: RUNTIME ERROR

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 10 9 8 6 5 4` view save

Error:

Traceback (most recent call last):
  File "input/code.py", line 20, in <module>
    other_node = n - (less_than_one[0]+1)
IndexError: list index out of range

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 10 9 8 7 6 5` 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 100000 99999 99998 99997 99996 99995 99994 99993 ...` view save

Test 7

Verdict: RUNTIME ERROR

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

correct output
`1 100000 1` view save

user output
`1 100000 1` view save

Error:

Traceback (most recent call last):
  File "input/code.py", line 20, in <module>
    other_node = n - (less_than_one[0]+1)
IndexError: list index out of range

Test 8

Verdict: WRONG ANSWER

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 100000 99999 99998 99997 99996 99995 99994 99993 ...` 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 100000 99989 99956 99906 99902 99879 99823 99674 ...` 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 100000 99887 98423 96194 94040 93581 92001 90168 ...` view save

Test 11

Verdict: RUNTIME ERROR

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

correct output
`2 2 6 4 10` view save

user output
`2 10 6 4 2` view save

Error:

Traceback (most recent call last):
  File "input/code.py", line 20, in <module>
    other_node = n - (less_than_one[0]+1)
IndexError: list index out of range

Test 12

Verdict: RUNTIME ERROR

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

correct output
`2 4 7 3 6` view save

user output
`2 7 6 4 3` view save

Error:

Traceback (most recent call last):
  File "input/code.py", line 20, in <module>
    other_node = n - (less_than_one[0]+1)
IndexError: list index out of range

Test 13

Verdict: RUNTIME ERROR

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

correct output
`2 3 6 2 5` view save

user output
`2 6 5 3 2` view save

Error:

Traceback (most recent call last):
  File "input/code.py", line 20, in <module>
    other_node = n - (less_than_one[0]+1)
IndexError: list index out of range

Test 14

Verdict: RUNTIME ERROR

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 65538 65537 65536 65535 65532 65531 65530 65529 ...` view save

Error:

Traceback (most recent call last):
  File "input/code.py", line 20, in <module>
    other_node = n - (less_than_one[0]+1)
IndexError: list index out of range

Test 15

Verdict: RUNTIME ERROR

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

correct output
`2 9 11 8 10` view save

user output
`2 11 10 9 8` view save

Error:

Traceback (most recent call last):
  File "input/code.py", line 20, in <module>
    other_node = n - (less_than_one[0]+1)
IndexError: list index out of range

Test 16

Verdict: RUNTIME ERROR

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

correct output
`2 5 7 4 6` view save

user output
`2 7 6 5 4` view save

Error:

Traceback (most recent call last):
  File "input/code.py", line 20, in <module>
    other_node = n - (less_than_one[0]+1)
IndexError: list index out of range

Test 17

Verdict: RUNTIME ERROR

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

correct output
`2 5 7 4 6` view save

user output
`2 7 6 5 4` view save

Error:

Traceback (most recent call last):
  File "input/code.py", line 20, in <module>
    other_node = n - (less_than_one[0]+1)
IndexError: list index out of range

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 10 9 8 7 6 5` view save

Test 19

Verdict: RUNTIME ERROR

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

correct output
`2 6 7 3 4` view save

user output
`2 7 6 4 3` view save

Error:

Traceback (most recent call last):
  File "input/code.py", line 20, in <module>
    other_node = n - (less_than_one[0]+1)
IndexError: list index out of range

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 8 7 6 5 4 5` view save

Test 21

Verdict: RUNTIME ERROR

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 10 9 8 7 6 3` view save

Error:

Traceback (most recent call last):
  File "input/code.py", line 20, in <module>
    other_node = n - (less_than_one[0]+1)
IndexError: list index out of range

Aalto Competitive Programming 2025 - 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 (aalto25f_004)