#include "gap.h"
#include <bits/stdc++.h>
using ll = long long;
ll gMaxDiff = 0;
std::set<ll> found;
int targetCount;
void maxDiff(ll min, ll max)
{
found.insert(min);
found.insert(max);
if (found.size() >= targetCount)
{
gMaxDiff = std::max(gMaxDiff, max - min);
return;
}
ll mid = min + (max - min) / 2;
ll s1Min, s1Max;
MinMax(min + 1, mid, &s1Min, &s1Max);
bool s1Pop = s1Min != -1;
ll s2Min, s2Max;
MinMax(mid + 1, max - 1, &s2Min, &s2Max);
bool s2Pop = s2Min != -1;
if (s1Pop && s2Pop)
{
gMaxDiff = std::max(gMaxDiff, s2Min - s1Max);
gMaxDiff = std::max(gMaxDiff, s1Min - min);
gMaxDiff = std::max(gMaxDiff, max - s2Max);
}
else if (!s1Pop && s2Pop)
{
gMaxDiff = std::max(gMaxDiff, s2Min - min);
gMaxDiff = std::max(gMaxDiff, max - s2Max);
}
else if (s1Pop && !s2Pop)
{
gMaxDiff = std::max(gMaxDiff, s1Min - min);
gMaxDiff = std::max(gMaxDiff, max - s1Max);
}
else if (!s1Pop && !s2Pop)
{
gMaxDiff = std::max(gMaxDiff, max - min);
}
if (s1Pop && s1Max - s1Min > gMaxDiff)
maxDiff(s1Min, s1Max);
if (s2Pop && s2Max - s2Min > gMaxDiff)
maxDiff(s2Min, s2Max);
}
long long findGap(int T, int N)
{
if (T == 1)
{
ll min = 0;
ll max = 1000000000000000000;
std::vector<ll> numbers(N);
for (int i = 0; 2 * i < N; i++)
{
ll nextMin, nextMax;
MinMax(min, max, &nextMin, &nextMax);
numbers[i] = nextMin;
numbers[numbers.size() - i - 1] = nextMax;
min = nextMin + 1;
max = nextMax - 1;
}
for (int i = 1; i < N; i++)
{
gMaxDiff = std::max(gMaxDiff, numbers[i] - numbers[i - 1]);
}
}
else
{
ll min, max;
MinMax(0, 1000000000000000000, &min, &max);
targetCount = N;
maxDiff(min, max);
}
return gMaxDiff;
}
