Submission #1015186

#	Time	Username	Problem	Language	Result	Execution time	Memory
1015186		vjudge1	Gap (APIO16_gap)	C++17	30 / 100	32 ms	1908 KiB

gap

#include<bits/stdc++.h>
#include "gap.h"

using namespace std;

typedef long long ll;


ll subtask1(int N);

// [0] = ans, [1] = mi, [2] = mx
vector<ll> subtask2(ll s = -1, ll e = 1'000'000'000'000'000'001)
{
  if(s > e) return {-1, -1, -1};
  ll mid = (s + e) / 2;
  ll mn1, mn2, mx1, mx2;
  
  MinMax(s, mid, &mn1, &mn2);
  MinMax(mid + 1, e, &mn2, &mx2);
  
  ll ans = -1;
  if(mn1 != -1)
    {
      vector<ll> v = subtask2(mn1 + 1, mx1 - 1);
      if(v[0] == -1)
	ans = max(ans, mx1 - mn1);
      else
	{
	  ans = max(v[0], ans);
	  ans = max(v[1] - mn1, ans);
	  ans = max(mx1 - v[2], ans);
	}
    }
  
  if(mn2 != -1)
    {
      vector<ll> v = subtask2(mn2 + 1, mx2 - 1);
      if(v[0] == -1)
	ans = max(ans, mx2 - mn2);
      else
	{
	  ans = max(v[0], ans);
	  ans = max(v[1] - mn2, ans);
	  ans = max(mx2 - v[2], ans);
	}
    }
  if(mn1 != -1 && mn2 != -1) ans = max(ans, mn2 - mx1);
  return {ans, mn1, mx2};
}

ll findGap(int T, int N)
{
  if(T == 1)
    return subtask1(N);
  return subtask2().at(0);
}


ll subtask1(int N)
{
  int i = 0, j = N - 1;
  ll s = 0, e = 1e18;
  ll *mn = new ll, *mx = new ll;

  vector<ll> v(N);
  
  while(i <= j && s <= e)
    {
      MinMax(s, e, mn, mx);
      v[i] = *mn;
      v[j] = *mx;
      i++, j--;
      s = *mn + 1;
      e = *mx - 1;
    }

  ll ans = 0;
  for(int i = 1; i < v.size(); i++)
    ans = max(ans, v[i] - v[i - 1]);
  return ans;
}

Compilation message (stderr)

gap.cpp: In function 'll subtask1(int)':
gap.cpp:78:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   78 |   for(int i = 1; i < v.size(); i++)
      |                  ~~^~~~~~~~~~
gap.cpp: In function 'std::vector<long long int> subtask2(ll, ll)':
gap.cpp:24:47: warning: 'mx1' may be used uninitialized in this function [-Wmaybe-uninitialized]
   24 |       vector<ll> v = subtask2(mn1 + 1, mx1 - 1);
      |                                               ^

• Subtask 1: 30 / 30
• Subtask 2: 0 / 70