Submission #841608

#	Time	Username	Problem	Language	Result	Execution time	Memory
841608		flashmt	Longest Trip (IOI23_longesttrip)	C++17	Compilation error	0 ms	0 KiB

longesttrip

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

vector<int> longest_trip(int n, int d)
{
  vector<int> c[2];
  c[0] = {0};
  for (int i = 1; i < n; i++)
  {
    int x = c[0].back();
    if (are_connected({i}, {x})) c[0].push_back(i);
    else c[1].push_back(i);
  }

  if (size(c[1]) > size(c[0]))
    swap(c[0], c[1]);

  if (empty(c[1]))
    return c[0];

  if (!are_connected(c[0], c[1]))
    return c[0];

  for (int u : {0, 1})
  {
    int v = u ^ 1;
    int x = c[v][0];

    if (are_connected({x}, {c[u][0]}))
    {
      reverse(begin(c[u]), end(c[u]));
      for (int y : c[v])
        c[u].push_back(y);
      return c[u];
    }

    if (are_connected({x}, {c[u].back()}))
    {
      for (int y : c[v])
        c[u].push_back(y);
      return c[u];
    }
  }

  // both c[0] and c[1] are cycles
  int low = 0, high = size(c[0]);
  while (high - low > 1)
  {
    int mid = (low + high) / 2;
    if (are_connected(vector<int>(begin(c[0]) + low, begin(c[0]) + mid), c[1])) high = mid;
    else low = mid;
  }
  int id0 = low;

  low = 0, high = size(c[1]);
  while (high - low > 1)
  {
    int mid = (low + high) / 2;
    if (are_connected(vector<int>(begin(c[1]) + low, begin(c[1]) + mid), {x})) high = mid;
    else low = mid;
  }
  int id1 = low;

  if (id0 < size(c[0]) - 1)
    rotate(begin(c[0]), begin(c[0]) + (id0 + 1), end(c[0]));
  rotate(begin(c[1]), begin(c[1]) + id1, end(c[1]));
  for (int i : c[1])
    c[0].push_back(i);
  return c[0];
}

Compilation message (stderr)

longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:60:75: error: 'x' was not declared in this scope
   60 |     if (are_connected(vector<int>(begin(c[1]) + low, begin(c[1]) + mid), {x})) high = mid;
      |                                                                           ^
longesttrip.cpp:60:77: error: could not convert '{<expression error>}' from '<brace-enclosed initializer list>' to 'std::vector<int>'
   60 |     if (are_connected(vector<int>(begin(c[1]) + low, begin(c[1]) + mid), {x})) high = mid;
      |                                                                             ^
      |                                                                             |
      |                                                                             <brace-enclosed initializer list>
longesttrip.cpp:65:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |   if (id0 < size(c[0]) - 1)
      |       ~~~~^~~~~~~~~~~~~~~~