CSES - BOI 2026 Mirror Day 2

Submission details
Task:	Distances
Sender:	saarixx
Submission time:	2026-04-17 12:38:00 +0300
Language:	C++ (C++23)
Status:	READY
Result:	10

Feedback
subtask	verdict	score
#1	TIME LIMIT EXCEEDED	0
#2	ACCEPTED	4
#3	ACCEPTED	6
#4	TIME LIMIT EXCEEDED	0
#5	TIME LIMIT EXCEEDED	0
#6	TIME LIMIT EXCEEDED	0

Test results
test	verdict	time	subtask
#1	ACCEPTED	0.00 s	1, 4, 6	details
#2	ACCEPTED	0.00 s	1, 2, 3, 4, 5, 6	details
#3	ACCEPTED	0.00 s	1, 3, 4, 5, 6	details
#4	ACCEPTED	0.00 s	1, 2, 4, 6	details
#5	ACCEPTED	0.00 s	1, 3, 4, 5, 6	details
#6	TIME LIMIT EXCEEDED	--	1, 4, 6	details
#7	ACCEPTED	0.00 s	1, 4, 6	details
#8	ACCEPTED	0.00 s	1, 2, 4, 6	details
#9	ACCEPTED	0.00 s	1, 3, 4, 5, 6	details
#10	TIME LIMIT EXCEEDED	--	1, 4, 5, 6	details
#11	TIME LIMIT EXCEEDED	--	1, 4, 6	details
#12	TIME LIMIT EXCEEDED	--	1, 4, 6	details
#13	ACCEPTED	0.00 s	1, 4, 6	details
#14	WRONG ANSWER	0.00 s	1, 6	details
#15	ACCEPTED	0.00 s	1, 2, 6	details
#16	TIME LIMIT EXCEEDED	--	4, 6	details
#17	TIME LIMIT EXCEEDED	--	4, 6	details
#18	ACCEPTED	0.00 s	3, 4, 5, 6	details
#19	TIME LIMIT EXCEEDED	--	4, 5, 6	details
#20	TIME LIMIT EXCEEDED	--	4, 5, 6	details
#21	TIME LIMIT EXCEEDED	--	5, 6	details
#22	TIME LIMIT EXCEEDED	--	5, 6	details
#23	ACCEPTED	0.00 s	2, 6	details
#24	ACCEPTED	0.00 s	3, 4, 5, 6	details
#25	TIME LIMIT EXCEEDED	--	4, 5, 6	details
#26	TIME LIMIT EXCEEDED	--	4, 5, 6	details
#27	TIME LIMIT EXCEEDED	--	5, 6	details
#28	TIME LIMIT EXCEEDED	--	5, 6	details
#29	ACCEPTED	0.00 s	2, 6	details
#30	ACCEPTED	0.00 s	3, 4, 5, 6	details
#31	TIME LIMIT EXCEEDED	--	4, 5, 6	details
#32	TIME LIMIT EXCEEDED	--	4, 5, 6	details
#33	TIME LIMIT EXCEEDED	--	4, 5, 6	details
#34	TIME LIMIT EXCEEDED	--	5, 6	details
#35	TIME LIMIT EXCEEDED	--	5, 6	details
#36	TIME LIMIT EXCEEDED	--	5, 6	details
#37	TIME LIMIT EXCEEDED	--	6	details
#38	TIME LIMIT EXCEEDED	--	6	details
#39	ACCEPTED	0.00 s	2, 6	details
#40	TIME LIMIT EXCEEDED	--	6	details
#41	TIME LIMIT EXCEEDED	--	6	details
#42	TIME LIMIT EXCEEDED	--	6	details
#43	TIME LIMIT EXCEEDED	--	6	details
#44	TIME LIMIT EXCEEDED	--	6	details

Code

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

bool is_perfect_square(ll d2) {
  if (d2 < 0) return false;
  if (d2 == 0) return true;
  ll s = round(sqrtl(d2));
  return s * s == d2;
}

int main() {
  int n;
  ll k;
  cin >> n >> k;
  if (n == 1) {
    cout << "0 0" << endl;
    return 0;
  }
  if (k == 0) {
    for (int i = 0; i < n; i++) {
      cout << i << " " << (ll)i * i << endl;
    }
    return 0;
  }
  ll max_possible = (ll)n * (n - 1) / 2;
  if (k == max_possible) {
    for (int i = 0; i < n; i++) {
      cout << i << " " << 0 << endl;
    }
    return 0;
  }
  vector<vector<pair<ll, ll>>> components;
  ll cur_k = k;
  ll cur_p = n;
  while (cur_k > 0 && cur_p > 0) {
    // Compute largest possible line clique size
    ll s = 2;
    while (s * (s - 1) / 2 <= cur_k && s <= cur_p) s++;
    s--;
    bool added = false;
    if (s >= 3) {
      ll t = s * (s - 1) / 2;
      ll rem_k = cur_k - t;
      ll rem_p = cur_p - s;
      // Only add if remaining is safe (0 or enough points for at least rem_k edges with small gadgets)
      if (rem_k == 0 || (rem_p >= 2 && rem_k <= rem_p)) {
        vector<pair<ll, ll>> comp;
        for (ll j = 0; j < s; j++) comp.emplace_back(j, 0);
        components.push_back(comp);
        cur_k -= t;
        cur_p -= s;
        added = true;
      }
    }
    if (!added && cur_k >= 4 && cur_p >= 4) {
      vector<pair<ll, ll>> comp = {{0, 0}, {1, 0}, {2, 0}, {0, 1}};
      components.push_back(comp);
      cur_k -= 4;
      cur_p -= 4;
      added = true;
    }
    if (!added && cur_k >= 2 && cur_p >= 3) {
      vector<pair<ll, ll>> comp = {{0, 0}, {1, 0}, {1, 1}};
      components.push_back(comp);
      cur_k -= 2;
      cur_p -= 3;
      added = true;
    }
    if (!added && cur_k >= 1 && cur_p >= 2) {
      vector<pair<ll, ll>> comp = {{0, 0}, {1, 0}};
      components.push_back(comp);
      cur_k -= 1;
      cur_p -= 2;
      added = true;
    }
    if (!added) {
      // Cannot add more edges safely; stop (isolates will be added below)
      break;
    }
  }
  // Add remaining isolates as single-point components
  for (ll i = 0; i < cur_p; i++) {
    vector<pair<ll, ll>> comp = {{0, 0}};
    components.push_back(comp);
  }
  // Place all components with sufficient separation to avoid extra integer distances
  vector<pair<ll, ll>> points;
  ll current_offset = 0;
  for (auto& comp : components) {
    ll offset = current_offset;
    while (true) {
      bool good = true;
      for (auto& p : comp) {
        ll px = p.first + offset;
        ll py = p.second;
        for (auto& ex : points) {
          ll dx = px - ex.first;
          ll dy = py - ex.second;
          ll d2 = dx * dx + dy * dy;
          if (is_perfect_square(d2)) {
            good = false;
            break;
          }
        }
        if (!good) break;
      }
      if (good) break;
      offset++;
    }
    // Add shifted points
    for (auto& p : comp) {
      points.emplace_back(p.first + offset, p.second);
    }
    // Update offset for next component
    ll max_x = 0;
    for (auto& pt : points) max_x = max(max_x, pt.first);
    current_offset = max_x + 100;  // generous gap for safety
  }
  // Output
  for (auto& p : points) {
    cout << p.first << " " << p.second << endl;
  }
  return 0;
}

Test details

Test 1

Subtask: 1, 4, 6

Verdict: ACCEPTED

input
`3 2` view save

correct output
`1 1 1 2 2 2` view save

user output
`0 0 1 0 1 1` view save

Test 2

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

Verdict: ACCEPTED

input
`1 0` view save

correct output
`1 0` view save

user output
`0 0` view save

Test 3

Subtask: 1, 3, 4, 5, 6

Verdict: ACCEPTED

input
`2 0` view save

correct output
`1 0 804289383 846930886` view save

user output
`0 0 1 1` view save

Test 4

Subtask: 1, 2, 4, 6

Verdict: ACCEPTED

input
`2 1` view save

correct output
`1 0 2 0` view save

user output
`0 0 1 0` view save

Test 5

Subtask: 1, 3, 4, 5, 6

Verdict: ACCEPTED

input
`3 0` view save

correct output
`1 0 804289383 846930886 681692777 714636915` view save

user output
`0 0 1 1 2 4` view save

Test 6

Subtask: 1, 4, 6

Verdict: TIME LIMIT EXCEEDED

input
`3 1` view save

correct output
`1 0 2 0 804289383 846930886` view save

user output
(empty)

Test 7

Subtask: 1, 4, 6

Verdict: ACCEPTED

input
`3 2` view save

correct output
`1 1 1 2 2 2` view save

user output
`0 0 1 0 1 1` view save

Test 8

Subtask: 1, 2, 4, 6

Verdict: ACCEPTED

input
`3 3` view save

correct output
`1 0 2 0 3 0` view save

user output
`0 0 1 0 2 0` view save

Test 9

Subtask: 1, 3, 4, 5, 6

Verdict: ACCEPTED

input
`4 0` view save

correct output
`1 0 804289383 846930886 681692777 714636915 957747793 424238335` view save

user output
`0 0 1 1 2 4 3 9` view save

Test 10

Subtask: 1, 4, 5, 6

Verdict: TIME LIMIT EXCEEDED

input
`4 1` view save

correct output
`1 0 2 0 804289383 846930886 681692777 714636915` view save

user output
(empty)

Test 11

Subtask: 1, 4, 6

Verdict: TIME LIMIT EXCEEDED

input
`4 2` view save

correct output
`21392 0 1 0 0 510510 804289383 846930886` view save

user output
(empty)

Test 12

Subtask: 1, 4, 6

Verdict: TIME LIMIT EXCEEDED

input
`4 3` view save

correct output
`1 0 2 0 3 0 804289383 846930886` view save

user output
(empty)

Test 13

Subtask: 1, 4, 6

Verdict: ACCEPTED

input
`4 4` view save

correct output
`21392 0 1 0 2 0 0 510510` view save

user output
`0 0 1 0 2 0 0 1` view save

Test 14

Subtask: 1, 6

Verdict: WRONG ANSWER

input
`4 5` view save

correct output
`21392 0 22600 0 1 0 0 510510` view save

user output
`0 0 1 0 2 0 0 1` view save

Test 15

Subtask: 1, 2, 6

Verdict: ACCEPTED

input
`4 6` view save

correct output
`1 0 2 0 3 0 4 0` view save

user output
`0 0 1 0 2 0 3 0` view save

Test 16

Subtask: 4, 6

Verdict: TIME LIMIT EXCEEDED

input
`5 5` view save

correct output
`21392 0 22600 0 1 0 0 510510 804289383 846930886` view save

user output
(empty)

Test 17

Subtask: 4, 6

Verdict: TIME LIMIT EXCEEDED

input
`6 5` view save

correct output
`21392 0 22600 0 1 0 0 510510 804289383 846930886 ...` view save

user output
(empty)

Test 18

Subtask: 3, 4, 5, 6

Verdict: ACCEPTED

input
`98 0` view save

correct output
`1 0 804289383 846930886 681692777 714636915 957747793 424238335 719885386 649760492 ...` view save

user output
`0 0 1 1 2 4 3 9 4 16 ...` view save

Test 19

Subtask: 4, 5, 6

Verdict: TIME LIMIT EXCEEDED

input
`98 97` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 20

Subtask: 4, 5, 6

Verdict: TIME LIMIT EXCEEDED

input
`98 98` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 21

Subtask: 5, 6

Verdict: TIME LIMIT EXCEEDED

input
`98 1185` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 22

Subtask: 5, 6

Verdict: TIME LIMIT EXCEEDED

input
`98 1188` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 23

Subtask: 2, 6

Verdict: ACCEPTED

input
`98 4753` view save

correct output
`1 0 2 0 3 0 4 0 5 0 ...` view save

user output
`0 0 1 0 2 0 3 0 4 0 ...` view save

Test 24

Subtask: 3, 4, 5, 6

Verdict: ACCEPTED

input
`99 0` view save

correct output
`1 0 804289383 846930886 681692777 714636915 957747793 424238335 719885386 649760492 ...` view save

user output
`0 0 1 1 2 4 3 9 4 16 ...` view save

Test 25

Subtask: 4, 5, 6

Verdict: TIME LIMIT EXCEEDED

input
`99 98` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 26

Subtask: 4, 5, 6

Verdict: TIME LIMIT EXCEEDED

input
`99 99` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 27

Subtask: 5, 6

Verdict: TIME LIMIT EXCEEDED

input
`99 1201` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 28

Subtask: 5, 6

Verdict: TIME LIMIT EXCEEDED

input
`99 1212` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 29

Subtask: 2, 6

Verdict: ACCEPTED

input
`99 4851` view save

correct output
`1 0 2 0 3 0 4 0 5 0 ...` view save

user output
`0 0 1 0 2 0 3 0 4 0 ...` view save

Test 30

Subtask: 3, 4, 5, 6

Verdict: ACCEPTED

input
`100 0` view save

correct output
`1 0 804289383 846930886 681692777 714636915 957747793 424238335 719885386 649760492 ...` view save

user output
`0 0 1 1 2 4 3 9 4 16 ...` view save

Test 31

Subtask: 4, 5, 6

Verdict: TIME LIMIT EXCEEDED

input
`100 1` view save

correct output
`1 0 2 0 804289383 846930886 681692777 714636915 957747793 424238335 ...` view save

user output
(empty)

Test 32

Subtask: 4, 5, 6

Verdict: TIME LIMIT EXCEEDED

input
`100 5` view save

correct output
`21392 0 22600 0 1 0 0 510510 804289383 846930886 ...` view save

user output
(empty)

Test 33

Subtask: 4, 5, 6

Verdict: TIME LIMIT EXCEEDED

input
`100 100` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 34

Subtask: 5, 6

Verdict: TIME LIMIT EXCEEDED

input
`100 1000` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 35

Subtask: 5, 6

Verdict: TIME LIMIT EXCEEDED

input
`100 1232` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 36

Subtask: 5, 6

Verdict: TIME LIMIT EXCEEDED

input
`100 1237` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 37

Subtask: 6

Verdict: TIME LIMIT EXCEEDED

input
`100 2222` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 38

Subtask: 6

Verdict: TIME LIMIT EXCEEDED

input
`100 3395` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 39

Subtask: 2, 6

Verdict: ACCEPTED

input
`100 4950` view save

correct output
`1 0 2 0 3 0 4 0 5 0 ...` view save

user output
`0 0 1 0 2 0 3 0 4 0 ...` view save

Test 40

Subtask: 6

Verdict: TIME LIMIT EXCEEDED

input
`100 4949` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 41

Subtask: 6

Verdict: TIME LIMIT EXCEEDED

input
`100 4948` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 42

Subtask: 6

Verdict: TIME LIMIT EXCEEDED

input
`100 4930` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 43

Subtask: 6

Verdict: TIME LIMIT EXCEEDED

input
`100 4920` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

Test 44

Subtask: 6

Verdict: TIME LIMIT EXCEEDED

input
`100 4900` view save

correct output
`21392 0 22600 0 30056 0 34848 0 38584 0 ...` view save

user output
(empty)

BOI 2026 Mirror Day 2

Distances

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 (saarixx)