CSES - Aalto Competitive Programming 2026 - wk2 - Homework

Submission details
Task:	Connect cities
Sender:	aalto26bh_039
Submission time:	2026-09-06 15:29:31 +0300
Language:	Java
Status:	READY
Result:	RUNTIME ERROR

Test results
test	verdict	time
#1	RUNTIME ERROR	0.11 s	details
#2	RUNTIME ERROR	0.11 s	details
#3	RUNTIME ERROR	0.11 s	details
#4	RUNTIME ERROR	0.11 s	details
#5	RUNTIME ERROR	0.11 s	details
#6	RUNTIME ERROR	0.41 s	details
#7	RUNTIME ERROR	0.41 s	details
#8	RUNTIME ERROR	0.40 s	details
#9	RUNTIME ERROR	0.40 s	details
#10	RUNTIME ERROR	0.41 s	details
#11	RUNTIME ERROR	0.12 s	details
#12	RUNTIME ERROR	0.10 s	details

Code

import java.util.*;

public class ConnectCities {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int n = input.nextInt();
        int m = input.nextInt();

        List<Integer> newConnections = new ArrayList<>();

        for (int i = 0; i < n-1; i++){
            newConnections.add(i+1);
        }

        List<Integer> oldConnections = new ArrayList<>();

        for (int i = 0; i < m; i++){
            input = new Scanner(System.in);
            int a = input.nextInt();
            int b = input.nextInt();
            oldConnections.add( Math.min(a, b));
        }

        newConnections.removeAll(oldConnections);

        System.out.println(newConnections.size());
        newConnections.forEach(city -> System.out.println(city + " " + (city + 1)));
    }

}

Test details

Test 1

Verdict: RUNTIME ERROR

input
`10 10 2 5 5 6 1 4 6 8 ...` view save

correct output
`2 1 2 2 7` view save

user output
(empty)

Error:

Exception in thread "main" java.util.NoSuchElementException
	at java.base/java.util.Scanner.throwFor(Scanner.java:945)
	at java.base/java.util.Scanner.next(Scanner.java:1602)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2267)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2221)
	at ConnectCities.main(ConnectCities.java:19)

Test 2

Verdict: RUNTIME ERROR

input
`10 10 3 9 6 8 9 10 7 8 ...` view save

correct output
`2 1 4 4 5` view save

user output
(empty)

Error:

Exception in thread "main" java.util.NoSuchElementException
	at java.base/java.util.Scanner.throwFor(Scanner.java:945)
	at java.base/java.util.Scanner.next(Scanner.java:1602)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2267)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2221)
	at ConnectCities.main(ConnectCities.java:19)

Test 3

Verdict: RUNTIME ERROR

input
`10 10 7 9 1 7 1 3 3 4 ...` view save

correct output
`0` view save

user output
(empty)

Error:

Exception in thread "main" java.util.NoSuchElementException
	at java.base/java.util.Scanner.throwFor(Scanner.java:945)
	at java.base/java.util.Scanner.next(Scanner.java:1602)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2267)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2221)
	at ConnectCities.main(ConnectCities.java:19)

Test 4

Verdict: RUNTIME ERROR

input
`10 10 4 8 5 9 4 9 2 7 ...` view save

correct output
`1 1 3` view save

user output
(empty)

Error:

Exception in thread "main" java.util.NoSuchElementException
	at java.base/java.util.Scanner.throwFor(Scanner.java:945)
	at java.base/java.util.Scanner.next(Scanner.java:1602)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2267)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2221)
	at ConnectCities.main(ConnectCities.java:19)

Test 5

Verdict: RUNTIME ERROR

input
`10 10 4 9 2 4 7 10 1 8 ...` view save

correct output
`0` view save

user output
(empty)

Error:

Exception in thread "main" java.util.NoSuchElementException
	at java.base/java.util.Scanner.throwFor(Scanner.java:945)
	at java.base/java.util.Scanner.next(Scanner.java:1602)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2267)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2221)
	at ConnectCities.main(ConnectCities.java:19)

Test 6

Verdict: RUNTIME ERROR

input
`100000 200000 7233 22146 94937 96203 6133 10731 98737 99193 ...` view save

correct output
`4785 1 2 2 3 3 4 4 5 ...` view save

user output
(empty)

Error:

Exception in thread "main" java.util.NoSuchElementException
	at java.base/java.util.Scanner.throwFor(Scanner.java:945)
	at java.base/java.util.Scanner.next(Scanner.java:1602)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2267)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2221)
	at ConnectCities.main(ConnectCities.java:19)

Test 7

Verdict: RUNTIME ERROR

input
`100000 200000 92950 93575 24401 88897 41796 99364 47106 50330 ...` view save

correct output
`4868 1 2 2 7 7 9 9 15 ...` view save

user output
(empty)

Error:

Exception in thread "main" java.util.NoSuchElementException
	at java.base/java.util.Scanner.throwFor(Scanner.java:945)
	at java.base/java.util.Scanner.next(Scanner.java:1602)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2267)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2221)
	at ConnectCities.main(ConnectCities.java:19)

Test 8

Verdict: RUNTIME ERROR

input
`100000 200000 15637 76736 79169 98809 4382 86557 73383 77029 ...` view save

correct output
`4683 1 9 9 20 20 27 27 28 ...` view save

user output
(empty)

Error:

Exception in thread "main" java.util.NoSuchElementException
	at java.base/java.util.Scanner.throwFor(Scanner.java:945)
	at java.base/java.util.Scanner.next(Scanner.java:1602)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2267)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2221)
	at ConnectCities.main(ConnectCities.java:19)

Test 9

Verdict: RUNTIME ERROR

input
`100000 200000 47932 66981 86401 99942 4353 27841 60492 67345 ...` view save

correct output
`4807 1 6 6 7 7 11 11 12 ...` view save

user output
(empty)

Error:

Exception in thread "main" java.util.NoSuchElementException
	at java.base/java.util.Scanner.throwFor(Scanner.java:945)
	at java.base/java.util.Scanner.next(Scanner.java:1602)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2267)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2221)
	at ConnectCities.main(ConnectCities.java:19)

Test 10

Verdict: RUNTIME ERROR

input
`100000 200000 6554 44548 76413 98555 5447 59589 70166 74434 ...` view save

correct output
`4786 1 2 2 18 18 21 21 27 ...` view save

user output
(empty)

Error:

Exception in thread "main" java.util.NoSuchElementException
	at java.base/java.util.Scanner.throwFor(Scanner.java:945)
	at java.base/java.util.Scanner.next(Scanner.java:1602)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2267)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2221)
	at ConnectCities.main(ConnectCities.java:19)

Test 11

Verdict: RUNTIME ERROR

input
`100000 1 1 2` view save

correct output
`99998 1 3 3 4 4 5 5 6 ...` view save

user output
(empty)

Error:

Exception in thread "main" java.util.NoSuchElementException
	at java.base/java.util.Scanner.throwFor(Scanner.java:945)
	at java.base/java.util.Scanner.next(Scanner.java:1602)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2267)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2221)
	at ConnectCities.main(ConnectCities.java:19)

Test 12

Verdict: RUNTIME ERROR

input
`10 9 2 5 5 6 1 4 6 8 ...` view save

correct output
`2 1 2 2 7` view save

user output
(empty)

Error:

Exception in thread "main" java.util.NoSuchElementException
	at java.base/java.util.Scanner.throwFor(Scanner.java:945)
	at java.base/java.util.Scanner.next(Scanner.java:1602)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2267)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2221)
	at ConnectCities.main(ConnectCities.java:19)

Aalto Competitive Programming 2026 - wk2 - Homework

Connect cities

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

Tasks

Submissions (aalto26bh_039)