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BOI 2026 Mirror Day 2

Sort

  • Start: 2026-04-17 10:00:00
  • End: 2026-04-17 15:00:00
Submission details
Task:Sort
Sender:FZiuzin
Submission time:2026-04-17 14:52:47 +0300
Language:C++ (C++20)
Status:READY
Result:0
Feedback
subtaskverdictscore
#10
#20
#30
#40
#50
#60
#70
Test results
testverdicttimesubtask
#10.00 s2, 6, 7details
#2ACCEPTED0.01 s1, 2, 3, 6, 7details
#3ACCEPTED0.00 s2, 6, 7details
#4ACCEPTED0.00 s1, 2, 3, 6, 7details
#5ACCEPTED0.00 s1, 2, 3, 6, 7details
#6ACCEPTED0.00 s1, 2, 3, 6, 7details
#7ACCEPTED0.00 s1, 2, 3, 6, 7details
#80.00 s1, 2, 3, 6, 7details
#9ACCEPTED0.00 s1, 2, 3, 6, 7details
#100.00 s1, 2, 3, 6, 7details
#110.00 s2, 6, 7details
#120.00 s2, 6, 7details
#130.00 s2, 6, 7details
#14ACCEPTED0.00 s2, 6, 7details
#150.00 s2, 6, 7details
#160.54 s3, 7details
#17ACCEPTED0.55 s3, 7details
#18ACCEPTED0.54 s3, 7details
#190.55 s3, 7details
#200.54 s3, 7details
#21ACCEPTED0.54 s3, 7details
#220.56 s3, 7details
#23ACCEPTED0.56 s3, 7details
#240.49 s4, 7details
#250.49 s4, 7details
#260.49 s4, 7details
#27ACCEPTED0.49 s4, 7details
#280.49 s4, 7details
#290.49 s4, 7details
#300.02 s5, 6, 7details
#310.02 s5, 6, 7details
#320.02 s5, 6, 7details
#330.02 s5, 6, 7details
#34ACCEPTED0.02 s5, 6, 7details
#350.02 s5, 6, 7details
#360.02 s6, 7details
#370.02 s6, 7details
#380.02 s6, 7details
#390.02 s6, 7details
#40ACCEPTED0.03 s6, 7details
#410.02 s6, 7details
#420.55 s7details
#430.56 s7details
#440.55 s7details
#450.55 s7details
#460.55 s7details
#470.55 s7details
#480.55 s7details
#49ACCEPTED0.55 s7details
#500.54 s7details
#510.55 s7details
#52ACCEPTED0.00 s1, 2, 3, 5, 6, 7details
#53ACCEPTED0.00 s1, 2, 3, 4, 5, 6, 7details
#54ACCEPTED0.00 s2, 5, 6, 7details
#550.00 s1, 2, 3, 4, 6, 7details
#560.00 s1, 2, 3, 6, 7details
#570.00 s6, 7details
#580.19 s3, 4, 7details
#590.19 s3, 7details
#600.00 s2, 6, 7details
#610.00 s2, 6, 7details
#620.00 s2, 6, 7details
#630.00 s2, 6, 7details
#640.00 s2, 6, 7details

Code

#include <bits/stdc++.h>

using namespace std;
#define int int64_t

const int INF = 1e14;
const int MAXN = 2e5 + 5;

#define pb push_back
#define all(a) a.begin(), a.end()

int n,q;
signed main()
{
    cin >> n >> q;
    vector<int> a(n);
    for (int i = 0;i < n;i++)
    {
        cin >> a[i];
        a[i]--;
    }
    vector<int> pref(n, 0);
    pref[0] = 0;
    for (int i = 1;i < n;i++)
    {
        if (a[i] < a[i - 1])
        {
            pref[i] = pref[i - 1] + 1;
        }
        else
        {
            pref[i] = pref[i - 1];
        }
    }
    vector<int> pref_mx(n, 0), suf_mi(n, 0);
    pref_mx[0] = a[0];
    for (int i = 1;i < n;i++)
    {
        pref_mx[i] = max(pref_mx[i - 1], a[i]);
    }
    suf_mi[n - 1] = a[n - 1];
    for (int i = n - 2;i >= 0;i--)
    {
        suf_mi[i] = min(suf_mi[i + 1], a[i]);
    }
    while (q--)
    {
        int l, r;
        cin >> l >> r;
        l--;
        r = n - r;
        if (l < r - 1 && pref[r - 1] - pref[l + 1] > 0)
        {
            cout << -1 << '\n';
            continue;
        }
        int cnt = 0;
        if (pref[l] > 0)
        {
            cnt++;
        }
        if (r != n - 1 && (pref[n - 1] - pref[r] > 0))
        {
            cnt++;
        }
        if (l < r - 1 && (a[l + 1] < pref_mx[l] || a[r - 1] > suf_mi[r]))
        {
            cout << -1 << '\n';
            continue;
        }
        cout << cnt << '\n';
    }
    return 0;
}

Test details

Test 1

Subtask: 2, 6, 7

Verdict:

input
6 3
3 1 4 1 5 9
4 1
3 3
2 5
view save

correct output
1
-1
2
view save

user output
1
1
2
view save

Feedback: Incorrect character on line 2 col 1: expected "-1", got "1"

Test 2

Subtask: 1, 2, 3, 6, 7

Verdict: ACCEPTED

input
2 1
548813503 548813503
1 1
view save

correct output
0
view save

user output
0
view save

Test 3

Subtask: 2, 6, 7

Verdict: ACCEPTED

input
1 1
417021999
1 1
view save

correct output
0
view save

user output
0
view save

Test 4

Subtask: 1, 2, 3, 6, 7

Verdict: ACCEPTED

input
10 10
20751947 20751947 20751947 494...
view save

correct output
-1
-1
1
1
-1
...
view save

user output
-1
-1
1
1
-1
...
view save

Test 5

Subtask: 1, 2, 3, 6, 7

Verdict: ACCEPTED

input
10 10
12780811 19475241 19475241 683...
view save

correct output
0
0
0
0
0
...
view save

user output
0
0
0
0
0
...
view save

Test 6

Subtask: 1, 2, 3, 6, 7

Verdict: ACCEPTED

input
10 10
14574963 14574963 14574963 864...
view save

correct output
0
0
0
0
0
...
view save

user output
0
0
0
0
0
...
view save

Test 7

Subtask: 1, 2, 3, 6, 7

Verdict: ACCEPTED

input
10 10
237541216 237541216 35036522 6...
view save

correct output
-1
-1
-1
2
-1
...
view save

user output
-1
-1
-1
2
-1
...
view save

Test 8

Subtask: 1, 2, 3, 6, 7

Verdict:

input
10 10
319425549 513116712 539199939 ...
view save

correct output
-1
-1
-1
-1
-1
...
view save

user output
-1
-1
-1
-1
-1
...
view save

Feedback: Incorrect character on line 7 col 1: expected "-1", got "1"

Test 9

Subtask: 1, 2, 3, 6, 7

Verdict: ACCEPTED

input
10 10
54363219 54363219 110986323 11...
view save

correct output
0
0
0
0
0
...
view save

user output
0
0
0
0
0
...
view save

Test 10

Subtask: 1, 2, 3, 6, 7

Verdict:

input
10 5
55687086 550701455 326656159 5...
view save

correct output
-1
-1
-1
-1
-1
view save

user output
-1
2
-1
-1
-1
view save

Feedback: Incorrect character on line 2 col 1: expected "-1", got "2"

Test 11

Subtask: 2, 6, 7

Verdict:

input
10 10
35889584 588130796 815837475 8...
view save

correct output
-1
-1
1
1
1
...
view save

user output
-1
-1
1
2
1
...
view save

Feedback: Incorrect character on line 4 col 1: expected "1", got "2"

Test 12

Subtask: 2, 6, 7

Verdict:

input
10 10
679842175 48724877 720966351 6...
view save

correct output
2
3
2
1
1
...
view save

user output
2
2
2
2
2
...
view save

Feedback: Incorrect character on line 2 col 1: expected "3", got "2"

Test 13

Subtask: 2, 6, 7

Verdict:

input
10 10
893310183 811950921 338863962 ...
view save

correct output
2
1
1
2
5
...
view save

user output
2
2
2
2
2
...
view save

Feedback: Incorrect character on line 2 col 1: expected "1", got "2"

Test 14

Subtask: 2, 6, 7

Verdict: ACCEPTED

input
10 10
221045363 282395847 441913686 ...
view save

correct output
0
0
0
0
0
...
view save

user output
0
0
0
0
0
...
view save

Test 15

Subtask: 2, 6, 7

Verdict:

input
10 10
509019662 983949268 960017302 ...
view save

correct output
3
-1
3
3
3
...
view save

user output
2
-1
2
2
2
...
view save

Feedback: Incorrect character on line 1 col 1: expected "3", got "2"

Test 16

Subtask: 3, 7

Verdict:

input
200000 200000
2277053 2277053 2277053 227705...
view save

correct output
-1
-1
-1
-1
-1
...
view save

user output
-1
-1
-1
-1
-1
...
view save

Feedback: Incorrect character on line 89153 col 1: expected "-1", got "2"

Test 17

Subtask: 3, 7

Verdict: ACCEPTED

input
200000 200000
6767 16596 16596 27202 37272 4...
view save

correct output
-1
-1
-1
-1
-1
...
view save

user output
-1
-1
-1
-1
-1
...
view save

Test 18

Subtask: 3, 7

Verdict: ACCEPTED

input
200000 200000
5393 5910 9099 15755 15755 164...
view save

correct output
-1
-1
-1
-1
-1
...
view save

user output
-1
-1
-1
-1
-1
...
view save

Test 19

Subtask: 3, 7

Verdict:

input
200000 200000
3779 4629 8999 10468 22605 227...
view save

correct output
-1
1
2
-1
-1
...
view save

user output
-1
1
2
-1
-1
...
view save

Feedback: Incorrect character on line 91658 col 1: expected "-1", got "2"

Test 20

Subtask: 3, 7

Verdict:

input
200000 200000
878 2791 10849 11861 13405 239...
view save

correct output
-1
-1
-1
-1
-1
...
view save

user output
-1
-1
-1
-1
-1
...
view save

Feedback: Incorrect character on line 80690 col 1: expected "-1", got "2"

Test 21

Subtask: 3, 7

Verdict: ACCEPTED

input
200000 200000
430 1479 1992 2829 7152 14093 ...
view save

correct output
-1
-1
-1
-1
-1
...
view save

user output
-1
-1
-1
-1
-1
...
view save

Test 22

Subtask: 3, 7

Verdict:

input
199997 200000
2733 10526 13882 14035 14689 3...
view save

correct output
-1
-1
-1
-1
-1
...
view save

user output
-1
-1
-1
-1
-1
...
view save

Feedback: Incorrect character on line 45048 col 1: expected "-1", got "2"

Test 23

Subtask: 3, 7

Verdict: ACCEPTED

input
200000 200000
12345 13538 15407 18490 18984 ...
view save

correct output
0
0
0
0
0
...
view save

user output
0
0
0
0
0
...
view save

Test 24

Subtask: 4, 7

Verdict:

input
200000 200000
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ...
view save

correct output
-1
1
-1
-1
-1
...
view save

user output
-1
2
-1
-1
-1
...
view save

Feedback: Incorrect character on line 2 col 1: expected "1", got "2"

Test 25

Subtask: 4, 7

Verdict:

input
200000 200000
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ...
view save

correct output
1
-1
1
-1
1
...
view save

user output
2
-1
2
-1
2
...
view save

Feedback: Incorrect character on line 1 col 1: expected "1", got "2"

Test 26

Subtask: 4, 7

Verdict:

input
200000 200000
2 2 1 1 2 1 2 1 2 2 2 1 1 1 2 ...
view save

correct output
4
3
2
2
6
...
view save

user output
2
2
2
2
2
...
view save

Feedback: Incorrect character on line 1 col 1: expected "4", got "2"

Test 27

Subtask: 4, 7

Verdict: ACCEPTED

input
200000 200000
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ...
view save

correct output
0
0
0
0
0
...
view save

user output
0
0
0
0
0
...
view save

Test 28

Subtask: 4, 7

Verdict:

input
200000 200000
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 ...
view save

correct output
8513
1099
35939
9299
19597
...
view save

user output
2
2
2
2
2
...
view save

Feedback: Incorrect character on line 1 col 1: expected "8513", got "2"

Test 29

Subtask: 4, 7

Verdict:

input
200000 200000
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 ...
view save

correct output
178345
169257
62115
96143
64796
...
view save

user output
2
2
2
2
2
...
view save

Feedback: Incorrect character on line 1 col 1: expected "178345", got "2"

Test 30

Subtask: 5, 6, 7

Verdict:

input
5000 5000
1 2 3 4 5 6 7 8 9 10 11 12 13 ...
view save

correct output
1
1
-1
1
-1
...
view save

user output
2
2
-1
2
-1
...
view save

Feedback: Incorrect character on line 1 col 1: expected "1", got "2"

Test 31

Subtask: 5, 6, 7

Verdict:

input
5000 5000
1 2 3 4 5 6 7 8 9 72 145 47 19...
view save

correct output
-1
2
-1
2
-1
...
view save

user output
-1
2
-1
2
-1
...
view save

Feedback: Incorrect character on line 10 col 1: expected "1", got "2"

Test 32

Subtask: 5, 6, 7

Verdict:

input
4999 5000
1 2 3 4 5 6 7 8 9 10 11 12 13 ...
view save

correct output
-1
2
-1
-1
-1
...
view save

user output
-1
2
-1
-1
-1
...
view save

Feedback: Incorrect character on line 116 col 1: expected "1", got "2"

Test 33

Subtask: 5, 6, 7

Verdict:

input
5000 5000
4033 4368 3086 3208 4313 388 8...
view save

correct output
3
3
3
3
11
...
view save

user output
2
2
2
2
2
...
view save

Feedback: Incorrect character on line 1 col 1: expected "3", got "2"

Test 34

Subtask: 5, 6, 7

Verdict: ACCEPTED

input
5000 5000
1 2 3 4 5 6 7 8 9 10 11 12 13 ...
view save

correct output
0
0
0
0
0
...
view save

user output
0
0
0
0
0
...
view save

Test 35

Subtask: 5, 6, 7

Verdict:

input
5000 5000
5000 4999 4998 4997 4996 4995 ...
view save

correct output
2039
1910
-1
687
673
...
view save

user output
2
2
-1
2
2
...
view save

Feedback: Incorrect character on line 1 col 2: expected "2039", got "2"

Test 36

Subtask: 6, 7

Verdict:

input
5000 5000
202010 457852 826471 926337 10...
view save

correct output
-1
-1
2
-1
-1
...
view save

user output
-1
-1
2
-1
-1
...
view save

Feedback: Incorrect character on line 7 col 1: expected "3", got "2"

Test 37

Subtask: 6, 7

Verdict:

input
5000 5000
190583 326486 431922 462939 72...
view save

correct output
-1
-1
-1
-1
2
...
view save

user output
-1
-1
-1
-1
2
...
view save

Feedback: Incorrect character on line 12 col 1: expected "1", got "2"

Test 38

Subtask: 6, 7

Verdict:

input
5000 5000
821998255 400550008 71790232 5...
view save

correct output
5
3
3
2
5
...
view save

user output
2
2
2
2
2
...
view save

Feedback: Incorrect character on line 1 col 1: expected "5", got "2"

Test 39

Subtask: 6, 7

Verdict:

input
5000 5000
266174928 446601941 191252234 ...
view save

correct output
3
3
414
4
3
...
view save

user output
2
2
2
2
2
...
view save

Feedback: Incorrect character on line 1 col 1: expected "3", got "2"

Test 40

Subtask: 6, 7

Verdict: ACCEPTED

input
5000 5000
11621 243915 243915 949123 137...
view save

correct output
0
0
0
0
0
...
view save

user output
0
0
0
0
0
...
view save

Test 41

Subtask: 6, 7

Verdict:

input
5000 5000
999767052 998555066 997822810 ...
view save

correct output
919
459
505
833
809
...
view save

user output
2
2
2
2
2
...
view save

Feedback: Incorrect character on line 1 col 1: expected "919", got "2"

Test 42

Subtask: 7

Verdict:

input
200000 200000
478025 478025 478025 478025 47...
view save

correct output
-1
-1
2
2
2
...
view save

user output
-1
-1
2
2
2
...
view save

Feedback: Incorrect character on line 6 col 1: expected "1", got "2"

Test 43

Subtask: 7

Verdict:

input
200000 200000
1810 2088 3022 3097 7459 7943 ...
view save

correct output
2
-1
-1
2
-1
...
view save

user output
2
-1
-1
2
-1
...
view save

Feedback: Incorrect character on line 17 col 1: expected "1", got "2"

Test 44

Subtask: 7

Verdict:

input
199531 200000
11328 26391 30353 37063 44412 ...
view save

correct output
-1
2
-1
2
2
...
view save

user output
-1
2
-1
2
2
...
view save

Feedback: Incorrect character on line 94 col 1: expected "1", got "2"

Test 45

Subtask: 7

Verdict:

input
200000 200000
106738201 369187074 412614650 ...
view save

correct output
2
12
3
19
3
...
view save

user output
2
2
2
2
2
...
view save

Feedback: Incorrect character on line 2 col 1: expected "12", got "2"

Test 46

Subtask: 7

Verdict:

input
200000 200000
670611290 43427363 8475380 309...
view save

correct output
3
5
3
3
3
...
view save

user output
2
2
2
2
2
...
view save

Feedback: Incorrect character on line 1 col 1: expected "3", got "2"

Test 47

Subtask: 7

Verdict:

input
200000 200000
907542569 504758282 948727805 ...
view save

correct output
3
33
3
3
3
...
view save

user output
2
2
2
2
2
...
view save

Feedback: Incorrect character on line 1 col 1: expected "3", got "2"

Test 48

Subtask: 7

Verdict:

input
200000 200000
487056731 460461648 142698485 ...
view save

correct output
3
3
3
3
3
...
view save

user output
2
2
2
2
2
...
view save

Feedback: Incorrect character on line 1 col 1: expected "3", got "2"

Test 49

Subtask: 7

Verdict: ACCEPTED

input
200000 200000
12772 23236 23236 23236 41149 ...
view save

correct output
0
0
0
0
0
...
view save

user output
0
0
0
0
0
...
view save

Test 50

Subtask: 7

Verdict:

input
200000 200000
999993539 999993361 999993361 ...
view save

correct output
125375
16687
-1
84781
46147
...
view save

user output
2
2
-1
2
2
...
view save

Feedback: Incorrect character on line 1 col 1: expected "125375", got "2"

Test 51

Subtask: 7

Verdict:

input
200000 200000
999993539 999993361 999993361 ...
view save

correct output
94788
177608
95881
56377
179957
...
view save

user output
2
2
2
2
2
...
view save

Feedback: Incorrect character on line 1 col 1: expected "94788", got "2"

Test 52

Subtask: 1, 2, 3, 5, 6, 7

Verdict: ACCEPTED

input
5 1
2 1 3 5 4
2 2
view save

correct output
2
view save

user output
2
view save

Test 53

Subtask: 1, 2, 3, 4, 5, 6, 7

Verdict: ACCEPTED

input
2 1
1 2
1 1
view save

correct output
0
view save

user output
0
view save

Test 54

Subtask: 2, 5, 6, 7

Verdict: ACCEPTED

input
4 1
2 1 4 3
3 2
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correct output
2
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user output
2
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Test 55

Subtask: 1, 2, 3, 4, 6, 7

Verdict:

input
10 10
1 1 1 1 2 2 1 1 2 2
7 1
2 6
4 5
...
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correct output
-1
1
-1
-1
-1
...
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user output
-1
1
-1
-1
-1
...
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Feedback: Incorrect character on line 7 col 1: expected "-1", got "0"

Test 56

Subtask: 1, 2, 3, 6, 7

Verdict:

input
10 10
181777772 181777772 181777772 ...
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correct output
-1
-1
-1
-1
-1
...
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user output
1
1
-1
-1
-1
...
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Feedback: Incorrect character on line 1 col 1: expected "-1", got "1"

Test 57

Subtask: 6, 7

Verdict:

input
100 10
92800811 524548163 939127795 9...
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correct output
-1
-1
3
-1
3
...
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user output
-1
-1
2
-1
2
...
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Feedback: Incorrect character on line 3 col 1: expected "3", got "2"

Test 58

Subtask: 3, 4, 7

Verdict:

input
100 100000
2 2 2 1 2 2 2 2 1 2 1 1 1 2 2 ...
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correct output
-1
-1
-1
-1
-1
...
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user output
-1
-1
-1
-1
-1
...
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Feedback: Incorrect character on line 14 col 1: expected "-1", got "2"

Test 59

Subtask: 3, 7

Verdict:

input
100 100000
172695325 172695325 172695325 ...
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correct output
-1
-1
-1
-1
-1
...
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user output
-1
-1
-1
-1
-1
...
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Feedback: Incorrect character on line 54 col 1: expected "-1", got "2"

Test 60

Subtask: 2, 6, 7

Verdict:

input
4 10
869194539 239439572 968540665 ...
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correct output
-1
2
-1
-1
-1
...
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user output
1
2
1
-1
-1
...
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Feedback: Incorrect character on line 1 col 1: expected "-1", got "1"

Test 61

Subtask: 2, 6, 7

Verdict:

input
10 10
55366041 112170735 112170735 5...
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correct output
-1
-1
2
1
1
...
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user output
-1
-1
2
1
2
...
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Feedback: Incorrect character on line 5 col 1: expected "1", got "2"

Test 62

Subtask: 2, 6, 7

Verdict:

input
10 10
156018639 156018639 445832758 ...
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correct output
-1
1
-1
-1
2
...
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user output
-1
2
1
-1
2
...
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Feedback: Incorrect character on line 2 col 1: expected "1", got "2"

Test 63

Subtask: 2, 6, 7

Verdict:

input
10 10
702507512 702507512 892090406 ...
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correct output
-1
2
-1
2
2
...
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user output
-1
2
-1
2
2
...
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Feedback: Incorrect character on line 9 col 1: expected "-1", got "1"

Test 64

Subtask: 2, 6, 7

Verdict:

input
10 10
720324490 720324490 720324490 ...
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correct output
-1
2
2
1
-1
...
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user output
-1
2
2
2
-1
...
view save

Feedback: Incorrect character on line 4 col 1: expected "1", got "2"

Tasks

A Distances-B Hamilton-C Sort-

Submissions (FZiuzin)

2026-04-17 14:54:38 132026-04-17 14:52:47 02026-04-17 14:50:59 02026-04-17 14:48:16 02026-04-17 14:47:20 02026-04-17 14:45:12 02026-04-17 14:43:10 02026-04-17 14:42:33 2026-04-17 14:34:09 112026-04-17 12:52:30 62026-04-17 12:26:53 62026-04-17 12:25:52 62026-04-17 12:18:40 6