Submission #416668

#	Time	Username	Problem	Language	Result	Execution time	Memory
416668		noshi91	The Collection Game (BOI21_swaps)	C++17	0 / 100	1 ms	200 KiB

swaps

#include <cstdint>
#include <vector>

namespace bitonic_sorter_impl {

  using u32 = std::uint32_t;

  std::vector<std::vector<std::pair<u32, u32>>> bitonic_sorter(const u32 n) {
    std::vector<std::vector<std::pair<u32, u32>>> ret;
    for (u32 w = 1; w < n; w *= 2) {
      for (u32 s = w; s != 0; s /= 2) {
        ret.push_back({});
        bool rev = false;
        for (u32 t = 0; t < n; t += 2 * w) {
          for (u32 k = 0; k != 2 * w; k += 2 * s) {
            for (u32 i = 0; i != s; i += 1) {
              u32 a = t + k + i;
              u32 b = t + k + i + s;
              if (b < n) {
                if (rev) {
                  ret.back().push_back({ b, a });
                }
                else {
                  ret.back().push_back({ a, b });
                }
              }
            }
          }
          rev = !rev;
        }
      }
    }
    return ret;
  }

} // namespace bitonic_sorter_impl

using bitonic_sorter_impl::bitonic_sorter;

#include <algorithm>
#include <numeric>
#include <utility>

#include <swaps.h>

void solve(int N, int V) {
  std::vector<int> a(N);
  std::iota(a.begin(), a.end(), 0);
  for (const auto &v : bitonic_sorter(N)) {
    for (const auto &[a, b] : v) {
      schedule(a + 1, b + 1);
    }
    const auto res = visit();
    for (int i = 0; i != v.size(); i += 1) {
      if (res[i]) {
        std::swap(a[v[i].first], a[v[i].second]);
      }
    }
  }
  std::reverse(a.begin(), a.end());
  for (auto& e : a) {
    e += 1;
  }
  answer(a);
}

Compilation message (stderr)

swaps.cpp: In function 'void solve(int, int)':
swaps.cpp:54:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<unsigned int, unsigned int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |     for (int i = 0; i != v.size(); i += 1) {
      |                     ~~^~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 3
• Subtask 4: 0 / 2
• Subtask 5: 0 / 9
• Subtask 6: 0 / 6
• Subtask 7: 0 / 9
• Subtask 8: 0 / 6
• Subtask 9: 0 / 21
• Subtask 10: 0 / 14
• Subtask 11: 0 / 9
• Subtask 12: 0 / 6