CSES - BOI 2026 Mirror Day 1

Submission details
Task:	Island
Sender:	Daniel_1997
Submission time:	2026-04-16 13:48:46 +0300
Language:	C++ (C++17)
Status:	READY
Result:	16

Feedback
subtask	verdict	score
#1	WRONG ANSWER	0
#2	WRONG ANSWER	0
#3	ACCEPTED	16
#4	WRONG ANSWER	0
#5	WRONG ANSWER	0

Test results
test	verdict	time	subtask
#1	WRONG ANSWER	0.01 s	1, 5	details
#2	ACCEPTED	0.01 s	1, 2, 3, 4, 5	details
#3	WRONG ANSWER	0.02 s	1, 5	details
#4	WRONG ANSWER	0.02 s	1, 5	details
#5	ACCEPTED	0.02 s	1, 3, 5	details
#6	WRONG ANSWER	0.02 s	1, 2, 4, 5	details
#7	WRONG ANSWER	0.02 s	1, 2, 4, 5	details
#8	WRONG ANSWER	0.02 s	1, 5	details
#9	WRONG ANSWER	0.02 s	1, 5	details
#10	ACCEPTED	0.02 s	1, 3, 4, 5	details
#11	ACCEPTED	0.02 s	1, 3, 5	details
#12	WRONG ANSWER	0.02 s	1, 4, 5	details
#13	ACCEPTED	0.02 s	1, 3, 4, 5	details
#14	ACCEPTED	0.02 s	1, 4, 5	details
#15	WRONG ANSWER	0.02 s	1, 5	details
#16	WRONG ANSWER	0.02 s	1, 5	details
#17	WRONG ANSWER	0.02 s	1, 5	details
#18	WRONG ANSWER	0.02 s	1, 5	details
#19	WRONG ANSWER	0.51 s	2, 4, 5	details
#20	WRONG ANSWER	0.50 s	2, 4, 5	details
#21	WRONG ANSWER	0.51 s	2, 4, 5	details
#22	WRONG ANSWER	0.69 s	2, 4, 5	details
#23	ACCEPTED	0.53 s	3, 5	details
#24	ACCEPTED	0.53 s	3, 5	details
#25	ACCEPTED	0.53 s	3, 5	details
#26	ACCEPTED	0.47 s	3, 5	details
#27	ACCEPTED	0.46 s	3, 4, 5	details
#28	ACCEPTED	0.36 s	3, 4, 5	details
#29	WRONG ANSWER	0.47 s	4, 5	details
#30	WRONG ANSWER	0.48 s	4, 5	details
#31	WRONG ANSWER	0.65 s	4, 5	details
#32	WRONG ANSWER	0.66 s	4, 5	details
#33	WRONG ANSWER	0.66 s	4, 5	details
#34	ACCEPTED	0.38 s	4, 5	details
#35	WRONG ANSWER	0.56 s	5	details
#36	WRONG ANSWER	0.56 s	5	details
#37	WRONG ANSWER	0.56 s	5	details
#38	WRONG ANSWER	0.56 s	5	details
#39	WRONG ANSWER	0.60 s	5	details
#40	WRONG ANSWER	0.59 s	5	details
#41	WRONG ANSWER	0.57 s	5	details
#42	WRONG ANSWER	0.58 s	5	details
#43	WRONG ANSWER	0.59 s	5	details
#44	WRONG ANSWER	0.59 s	5	details

Code

#include <bits/stdc++.h>
using namespace std;
#define fr first
#define sc second
#define pb push_back
#define int long long
#define all(x) x.begin(), x.end()
#define ios ios_base::sync_with_stdio(0); cin.tie(0), cout.tie(0)
 
const int oo = 1e18;
const int mod = 1e8 + 7;
const int my[8]={0, 0, 1, -1, 1, 1, -1, -1};
const int mx[8]={1, -1, 0, 0, 1, -1, -1, 1};

const int N = 1001;
vector<vector<bool> > visi(N + 1, vector<bool> (N + 1, 0));
vector<vector<int> > id(N + 1, vector<int> (N + 1, 0));
vector<int> d(N + 1,0);
vector<int> p(N + 1,0);

void bfs(int x1, int y1, const int& n, const vector<string>& v)
{
    queue<pair<int,int> > q;
    visi[x1][y1] = 1;
    q.push({x1, y1});

    while(!q.empty())
    {
        auto [x,y] = q.front();q.pop();

        for(int i = 0; i < 4; i++)
        {
            int nx = x + mx[i];
            int ny = y + my[i];

            if(nx >= 1 && ny >= 1 && nx <= n && ny <= n && !visi[nx][ny] && v[nx][ny] != '.')
            {
                d[id[nx][ny]] = d[id[x][y]] + 1;
                visi[nx][ny] = 1;
                p[id[nx][ny]] = id[x][y];
                q.push({nx, ny});
            }
        }
    }
} 

struct infeliz {
    vector<vector<int> >bl;
    infeliz(int n, const vector<int>& f)
    {
        bl.assign(31, vector<int>(n + 1));

        bl[0] = f;

        for(int i = 1; i <= 29; i++)
        {
            for(int j = 1; j <= n; j++)
            {
                bl[i][j] = bl[i - 1][bl[i - 1][j]];
            }
        }
    }

    int lca(int a,int b)
    {
        if(a == b) {
            return a;
        }
        if(d[a] > d[b]) {
            swap(a,b);
        }
 
        int dist = abs(d[a] - d[b]);
 
        for(int i = 0; i < 27; i++)
        {
            if(dist & (1 << i)) {
                b = bl[i][b];
            }
        }
        //cout << a << " " << b << endl;
 
        if(a == b) {
            return a;
        }
 
        for(int i = 26; i >= 0; i--) {
            int x = bl[i][a];
            int y = bl[i][b];
            if(x == y)continue;
            a = x;
            b = y;
        }
 
        return bl[0][a];

    }

};

void solve() {
    
    int n, q;
    cin >> n >> q;

    vector<string> v(n + 1);

    int ct = 0;

    for(int i = 1; i <= n; i++)
    {
        cin >> v[i];
        v[i] = '0' + v[i];
        for(int j = 1; j <= n; j++)
        {
            if(v[i][j] == '#')
            {
                id[i][j] = ct;
                //cerr << id[i][j] << endl;
                ct++;
            }
        }
    }

    d.assign(ct + 1,0);
    p.assign(ct + 1,0);


    bool f = 0;
    
    for(int i = 1; i <= n; i++)
    {
        for(int j = 1; j <= n; j++)
        {
            if(v[i][j] == '#')
            {
                p[id[i][j]] = id[i][j];
                f = 1;
                bfs(i, j, n, v);
                break;
            }
        }
        if(f)break;
    }

    
    infeliz B(ct, p);

    while(q--)
    {
        int x1, y1, x2, y2;
        cin >> x1 >> y1 >> x2 >> y2;

        int a = id[x1][y1];
        int b = id[x2][y2];
        int pa = B.lca(a,b);

        cout << abs(d[pa] - d[a]) + abs(d[pa] - d[b]) << endl;

    }


    
}
 
int32_t main() {
    ios;
    int t = 1;
    //cin >> t;
    while(t--)solve();
}

Test details

Test 1

Subtask: 1, 5

Verdict: WRONG ANSWER

input
`8 4 ........ ..####.. .##.###. .##.###. ...` view save

correct output
`5 0 17 3` view save

user output
`5 0 17 5` view save

Feedback: Incorrect character on line 4 col 1: expected "3", got "5"

Test 2

Subtask: 1, 2, 3, 4, 5

Verdict: ACCEPTED

input
`3 1 ... .#. ... 2 2 2 2` view save

correct output
`0` view save

user output
`0` view save

Test 3

Subtask: 1, 5

Verdict: WRONG ANSWER

input
`199 196 .................................` view save

correct output
`468 605 825 532 496 ...` view save

user output
`468 605 825 532 496 ...` view save

Feedback: Incorrect character on line 9 col 3: expected "205", got "207"

Test 4

Subtask: 1, 5

Verdict: WRONG ANSWER

input
`200 200 .................................` view save

correct output
`112 347 142 459 239 ...` view save

user output
`114 353 142 459 249 ...` view save

Feedback: Incorrect character on line 1 col 3: expected "112", got "114"

Test 5

Subtask: 1, 3, 5

Verdict: ACCEPTED

input
`200 200 .................................` view save

correct output
`381 544 94 532 98 ...` view save

user output
`381 544 94 532 98 ...` view save

Test 6

Subtask: 1, 2, 4, 5

Verdict: WRONG ANSWER

input
`200 200 .................................` view save

correct output
`133 73 81 82 53 ...` view save

user output
`205 235 209 132 75 ...` view save

Feedback: Incorrect character on line 1 col 1: expected "133", got "205"

Test 7

Subtask: 1, 2, 4, 5

Verdict: WRONG ANSWER

input
`200 200 .................................` view save

correct output
`139 52 101 14 144 ...` view save

user output
`139 132 227 92 280 ...` view save

Feedback: Incorrect character on line 2 col 1: expected "52", got "132"

Test 8

Subtask: 1, 5

Verdict: WRONG ANSWER

input
`200 200 .................................` view save

correct output
`236 555 878 632 829 ...` view save

user output
`236 555 878 638 829 ...` view save

Feedback: Incorrect character on line 4 col 3: expected "632", got "638"

Test 9

Subtask: 1, 5

Verdict: WRONG ANSWER

input
`200 200 .................................` view save

correct output
`425 296 698 577 422 ...` view save

user output
`425 296 698 577 422 ...` view save

Feedback: Incorrect character on line 40 col 1: expected "68", got "70"

Test 10

Subtask: 1, 3, 4, 5

Verdict: ACCEPTED

input
`200 200 .................................` view save

correct output
`1365 7284 11808 6136 9283 ...` view save

user output
`1365 7284 11808 6136 9283 ...` view save

Test 11

Subtask: 1, 3, 5

Verdict: ACCEPTED

input
`200 200 .................................` view save

correct output
`6292 17954 16728 8938 1335 ...` view save

user output
`6292 17954 16728 8938 1335 ...` view save

Test 12

Subtask: 1, 4, 5

Verdict: WRONG ANSWER

input
`200 200 .................................` view save

correct output
`27 141 269 127 61 ...` view save

user output
`171 141 269 127 89 ...` view save

Feedback: Incorrect character on line 1 col 1: expected "27", got "171"

Test 13

Subtask: 1, 3, 4, 5

Verdict: ACCEPTED

input
`200 200 .................................` view save

correct output
`19552 19544 19478 19402 19456 ...` view save

user output
`19552 19544 19478 19402 19456 ...` view save

Test 14

Subtask: 1, 4, 5

Verdict: ACCEPTED

input
`200 200 .................................` view save

correct output
`17624 17515 17468 17689 17510 ...` view save

user output
`17624 17515 17468 17689 17510 ...` view save

Test 15

Subtask: 1, 5

Verdict: WRONG ANSWER

input
`200 200 .................................` view save

correct output
`1584 1433 567 2248 1030 ...` view save

user output
`1586 1433 567 2248 1032 ...` view save

Feedback: Incorrect character on line 1 col 4: expected "1584", got "1586"

Test 16

Subtask: 1, 5

Verdict: WRONG ANSWER

input
`200 200 .................................` view save

correct output
`5872 6374 60 323 5311 ...` view save

user output
`5876 6374 60 327 5311 ...` view save

Feedback: Incorrect character on line 1 col 4: expected "5872", got "5876"

Test 17

Subtask: 1, 5

Verdict: WRONG ANSWER

input
`200 200 .................................` view save

correct output
`1852 213 252 3861 1835 ...` view save

user output
`1852 215 252 3861 1843 ...` view save

Feedback: Incorrect character on line 2 col 3: expected "213", got "215"

Test 18

Subtask: 1, 5

Verdict: WRONG ANSWER

input
`200 200 .................................` view save

correct output
`1564 2709 866 1318 1758 ...` view save

user output
`1564 2711 866 1318 1758 ...` view save

Feedback: Incorrect character on line 2 col 3: expected "2709", got "2711"

Test 19

Subtask: 2, 4, 5

Verdict: WRONG ANSWER

input
`997 100000 .................................` view save

correct output
`150 531 370 518 508 ...` view save

user output
`284 531 474 518 508 ...` view save

Feedback: Incorrect character on line 1 col 1: expected "150", got "284"

Test 20

Subtask: 2, 4, 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`390 278 783 1269 249 ...` view save

user output
`850 928 1431 1401 1371 ...` view save

Feedback: Incorrect character on line 1 col 1: expected "390", got "850"

Test 21

Subtask: 2, 4, 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`63 142 813 683 731 ...` view save

user output
`349 1086 831 765 1107 ...` view save

Feedback: Incorrect character on line 1 col 1: expected "63", got "349"

Test 22

Subtask: 2, 4, 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`949 876 1209 494 1033 ...` view save

user output
`1081 2094 1427 1684 1107 ...` view save

Feedback: Incorrect character on line 1 col 1: expected "949", got "1081"

Test 23

Subtask: 3, 5

Verdict: ACCEPTED

input
`997 100000 .................................` view save

correct output
`714 2683 3699 2085 7850 ...` view save

user output
`714 2683 3699 2085 7850 ...` view save

Test 24

Subtask: 3, 5

Verdict: ACCEPTED

input
`1000 100000 .................................` view save

correct output
`5081 1819 1050 4610 528 ...` view save

user output
`5081 1819 1050 4610 528 ...` view save

Test 25

Subtask: 3, 5

Verdict: ACCEPTED

input
`1000 100000 .................................` view save

correct output
`3554 6322 6648 2882 1490 ...` view save

user output
`3554 6322 6648 2882 1490 ...` view save

Test 26

Subtask: 3, 5

Verdict: ACCEPTED

input
`1000 100000 .................................` view save

correct output
`433976 81646 87810 48080 110879 ...` view save

user output
`433976 81646 87810 48080 110879 ...` view save

Test 27

Subtask: 3, 4, 5

Verdict: ACCEPTED

input
`1000 100000 .................................` view save

correct output
`207982 140036 208364 51912 56826 ...` view save

user output
`207982 140036 208364 51912 56826 ...` view save

Test 28

Subtask: 3, 4, 5

Verdict: ACCEPTED

input
`1000 100000 .................................` view save

correct output
`497525 497563 498000 496804 497335 ...` view save

user output
`497525 497563 498000 496804 497335 ...` view save

Test 29

Subtask: 4, 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`38580 2097 9795 38033 1639 ...` view save

user output
`38580 2097 9795 38441 1639 ...` view save

Feedback: Incorrect character on line 4 col 3: expected "38033", got "38441"

Test 30

Subtask: 4, 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`33 20900 25028 1782 13599 ...` view save

user output
`169 20900 25028 1782 13789 ...` view save

Feedback: Incorrect character on line 1 col 1: expected "33", got "169"

Test 31

Subtask: 4, 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`1421 1122 1840 834 443 ...` view save

user output
`1421 1176 1840 1230 535 ...` view save

Feedback: Incorrect character on line 2 col 3: expected "1122", got "1176"

Test 32

Subtask: 4, 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`1378 1751 2274 250 811 ...` view save

user output
`1482 1751 2274 1054 1119 ...` view save

Feedback: Incorrect character on line 1 col 2: expected "1378", got "1482"

Test 33

Subtask: 4, 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`1126 886 544 223 272 ...` view save

user output
`1162 886 560 567 272 ...` view save

Feedback: Incorrect character on line 1 col 3: expected "1126", got "1162"

Test 34

Subtask: 4, 5

Verdict: ACCEPTED

input
`1000 100000 .................................` view save

correct output
`327286 447779 447534 448307 446997 ...` view save

user output
`327286 447779 447534 448307 446997 ...` view save

Test 35

Subtask: 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`2597 1473 1933 2691 1837 ...` view save

user output
`2599 1473 1933 2691 1837 ...` view save

Feedback: Incorrect character on line 1 col 4: expected "2597", got "2599"

Test 36

Subtask: 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`553 4357 3147 6951 1573 ...` view save

user output
`553 4357 3147 6951 1573 ...` view save

Feedback: Incorrect character on line 8 col 4: expected "3725", got "3727"

Test 37

Subtask: 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`1723 2039 1871 5638 4256 ...` view save

user output
`1725 2039 1873 5638 4256 ...` view save

Feedback: Incorrect character on line 1 col 4: expected "1723", got "1725"

Test 38

Subtask: 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`1546 704 2796 3802 1870 ...` view save

user output
`1546 704 2796 3802 1872 ...` view save

Feedback: Incorrect character on line 5 col 4: expected "1870", got "1872"

Test 39

Subtask: 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`3115 2042 2083 3227 740 ...` view save

user output
`3115 2042 2087 3235 752 ...` view save

Feedback: Incorrect character on line 3 col 4: expected "2083", got "2087"

Test 40

Subtask: 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`5222 3211 5230 1772 2310 ...` view save

user output
`5222 3217 5234 1772 2314 ...` view save

Feedback: Incorrect character on line 2 col 4: expected "3211", got "3217"

Test 41

Subtask: 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`159214 68851 200821 141404 145704 ...` view save

user output
`159214 68851 200823 141404 145706 ...` view save

Feedback: Incorrect character on line 3 col 6: expected "200821", got "200823"

Test 42

Subtask: 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`1843 25028 124430 84542 131339 ...` view save

user output
`1843 25028 124430 84544 131339 ...` view save

Feedback: Incorrect character on line 4 col 5: expected "84542", got "84544"

Test 43

Subtask: 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`111206 75799 12026 142133 20483 ...` view save

user output
`111210 75799 12026 142133 20483 ...` view save

Feedback: Incorrect character on line 1 col 5: expected "111206", got "111210"

Test 44

Subtask: 5

Verdict: WRONG ANSWER

input
`1000 100000 .................................` view save

correct output
`20360 9075 12187 54923 54574 ...` view save

user output
`20360 9075 12187 54923 54574 ...` view save

Feedback: Incorrect character on line 8 col 4: expected "43127", got "43131"

BOI 2026 Mirror Day 1

Island

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

Test 22

Test 23

Test 24

Test 25

Test 26

Test 27

Test 28

Test 29

Test 30

Test 31

Test 32

Test 33

Test 34

Test 35

Test 36

Test 37

Test 38

Test 39

Test 40

Test 41

Test 42

Test 43

Test 44

Tasks

Submissions (Daniel_1997)