Submission #1029586

#	Time	Username	Problem	Language	Result	Execution time	Memory
1029586		kunzaZa183	Teleporters (IOI08_teleporters)	C++17	100 / 100	444 ms	40628 KiB

teleporters

#include <bits/stdc++.h>
using namespace std;
int tp[2000001];
bool vb[2000005];
int main() {
  cin.tie(0)->sync_with_stdio(0);
  cin.exceptions(cin.failbit);
  int n, m;
  cin >> n >> m;
  vector<int> vi;
  for (int i = 0; i < n; i++) {
    int a, b;
    cin >> a >> b;
    vi.push_back(a), vi.push_back(b);
    tp[a] = b, tp[b] = a;
  }
  vi.push_back(0);
  sort(vi.begin(), vi.end());
  // for (auto a : vpii) cout << a.first << " " << a.second << "\n";
  vector<int> cyc;
  int special;
  for (int i = 0; i < vi.size(); i++)
    if (!vb[i]) {
      // cout << "I = " << i << '\n';
      int cy = 0;
      int cur = i;
      while (1) {
        if (cur == vi.size()) {
          special = cy - 1;
          break;
        }
        // cout << cur << "\n";
        if (vb[cur]) {
          cyc.push_back(cy);
          break;
        }
        vb[cur] = 1;
        cy++;
        cur = lower_bound(vi.begin(), vi.end(), tp[vi[cur]]) - vi.begin() + 1;
      };
    }
  // for (auto a : cyc) cout << a << ' ';
  // cout << "\n";
  sort(cyc.begin(), cyc.end(), greater<int>());
  if (m >= cyc.size()) {
    int x = (m - cyc.size());
    int val = x / 2 * 4 + x % 2;
    cout << special + accumulate(cyc.begin(), cyc.end(), 0) + cyc.size() * 2 +
                val
         << "\n";
  } else
    cout << special + accumulate(cyc.begin(), cyc.begin() + m, 0) + 2 * m
         << "\n";
}

Compilation message (stderr)

teleporters.cpp: In function 'int main()':
teleporters.cpp:22:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |   for (int i = 0; i < vi.size(); i++)
      |                   ~~^~~~~~~~~~~
teleporters.cpp:28:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |         if (cur == vi.size()) {
      |             ~~~~^~~~~~~~~~~~
teleporters.cpp:45:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |   if (m >= cyc.size()) {
      |       ~~^~~~~~~~~~~~~
teleporters.cpp:48:21: warning: 'special' may be used uninitialized in this function [-Wmaybe-uninitialized]
   48 |     cout << special + accumulate(cyc.begin(), cyc.end(), 0) + cyc.size() * 2 +
      |             ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
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• Subtask 20: 5 / 5