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Submission #213008

# Submission time Handle Problem Language Result Execution time Memory
213008 2020-03-24T18:34:09 Z arman_ferdous Strange Device (APIO19_strange_device) C++17
10 / 100
 577 ms 21608 KB 
/* at time = 0, (x, y) = (0, 0)
 * we need to find minimum t > 0, such that (x, y) = 0 again ie. the cycle period.
 * now, y = 0 = t % B => t = K * B (for some integer K)
 * putting t in x's eqn and simplifying gives us a nice formula
 * K * (B + 1) % A = 0
 * from here it is easy to find K's value. 
 * answering queries are just merging intervals
 */

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

using ll = long long;
const ll oo = 2e18;

vector<pair<ll,ll>> interval;

int main () {
  int n;
  ll A, B;
  scanf("%d %lld %lld", &n, &A, &B);

  int inf = 0, all = 0; ll sum = 0;
  ll g = __gcd(A, B + 1);
  ll K = A / g;
  ll T = K * B;

  if(K > oo / B) inf = 1;
  while(n--) {
    ll l, r;
    scanf("%lld %lld", &l, &r);

    if(r - l + 1 >= T) {
      all = 1;
      break;
    } sum += r - l + 1;

    ll le = l % T;
    ll ri = r % T;
    if(le <= ri) {
      interval.push_back({le, ri});

    }
    else {
      interval.push_back({0, ri});
      interval.push_back({le, T - 1});
    }
  }

  if(all) printf("%lld\n", T);
  else if(inf) printf("%lld\n", sum);
  else {
    ll ans = 0;
    sort(interval.begin(), interval.end());
    for(int i = 0; i < (int)interval.size(); i++) {
      ans += interval[i].second - interval[i].first + 1;
      if(i) ans -= max(interval[i - 1].second - interval[i].first + 1, 0ll);
    }
    printf("%lld\n", ans);
  }
  return 0;
}

Compilation message

strange_device.cpp: In function 'int main()':
strange_device.cpp:21:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %lld %lld", &n, &A, &B);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
strange_device.cpp:31:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%lld %lld", &l, &r);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 256 KB Output is correct
2 Incorrect 10 ms 1152 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #2
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 384 KB Output is correct
2 Correct 5 ms 256 KB Output is correct
3 Correct 5 ms 256 KB Output is correct
4 Correct 4 ms 256 KB Output is correct
5 Incorrect 4 ms 256 KB Output isn't correct

Subtask #3
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 256 KB Output is correct
2 Incorrect 5 ms 384 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #4
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 256 KB Output is correct
2 Correct 527 ms 21592 KB Output is correct
3 Correct 515 ms 21520 KB Output is correct
4 Correct 508 ms 21456 KB Output is correct

Subtask #5
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 256 KB Output is correct
2 Correct 527 ms 21592 KB Output is correct
3 Correct 515 ms 21520 KB Output is correct
4 Correct 508 ms 21456 KB Output is correct
5 Correct 4 ms 384 KB Output is correct
6 Correct 508 ms 21448 KB Output is correct
7 Correct 517 ms 21456 KB Output is correct
8 Correct 497 ms 21456 KB Output is correct
9 Correct 556 ms 21608 KB Output is correct

Subtask #6
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 256 KB Output is correct
2 Correct 527 ms 21592 KB Output is correct
3 Correct 515 ms 21520 KB Output is correct
4 Correct 508 ms 21456 KB Output is correct
5 Correct 4 ms 256 KB Output is correct
6 Correct 56 ms 5736 KB Output is correct
7 Correct 60 ms 5736 KB Output is correct
8 Correct 53 ms 5732 KB Output is correct
9 Correct 57 ms 5732 KB Output is correct
10 Correct 58 ms 5732 KB Output is correct
11 Correct 57 ms 5736 KB Output is correct
12 Correct 56 ms 5736 KB Output is correct
13 Correct 62 ms 5736 KB Output is correct
14 Correct 58 ms 5728 KB Output is correct
15 Incorrect 63 ms 5732 KB Output isn't correct
16 Halted 0 ms 0 KB -

Subtask #7
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 384 KB Output is correct
2 Correct 67 ms 5876 KB Output is correct
3 Correct 61 ms 5732 KB Output is correct
4 Correct 577 ms 21456 KB Output is correct
5 Correct 57 ms 5736 KB Output is correct
6 Correct 56 ms 5732 KB Output is correct
7 Correct 59 ms 5736 KB Output is correct
8 Correct 59 ms 5736 KB Output is correct
9 Correct 55 ms 5736 KB Output is correct
10 Correct 57 ms 5728 KB Output is correct
11 Correct 65 ms 6016 KB Output is correct
12 Correct 53 ms 5736 KB Output is correct
13 Correct 60 ms 5732 KB Output is correct
14 Incorrect 570 ms 21436 KB Output isn't correct
15 Halted 0 ms 0 KB -

Subtask #8
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 256 KB Output is correct
2 Incorrect 10 ms 1152 KB Output isn't correct
3 Halted 0 ms 0 KB -