#include "gap.h"
#include <vector>
#include <iostream>
#include <random>
#include <algorithm>
using namespace std;
const long long INF = 1e18;
mt19937_64 rnd(23478612);
inline long long random(long long MIN, long long MAX) {
return rnd() % (MAX - MIN + 1) + MIN;
}
long long calc_cost(const vector<long long> &seq) {
long long res = 0;
for (int i = 0; i + 1 < (int)seq.size(); i++)
res = max(res, seq[i + 1] - seq[i]);
return res;
}
namespace SUB1 {
long long findGap(int N) {
vector<long long> seq(N);
long long L = 0, R = INF;
for (int i = 0, j = N - 1; i <= j; i++, j--) {
MinMax(L, R, &seq[i], &seq[j]);
L = seq[i] + 1, R = seq[j] - 1;
}
return calc_cost(seq);
}
}
namespace SUB2 {
long long findGap(int N) {
vector<long long> marks = {0};
for (int i = 0; i < 2 * N; i++)
marks.push_back(random(1, INF));
marks.push_back(INF + 1);
sort(marks.begin(), marks.end());
vector<pair<long long, long long>> rep;
for (int i = 0; i + 1 < (int)marks.size(); i++) {
long long l, r;
MinMax(marks[i], marks[i + 1], &l, &r);
rep.emplace_back(l, r);
}
long long ans = 0;
for (int i = 0; i + 1 < (int)marks.size(); i++) {
ans = max(ans, rep[i + 1].first - rep[i].second);
}
return ans;
}
}
long long findGap(int T, int N) {
return (T == 1) ? SUB1::findGap(N) : SUB2::findGap(N);
}
