Submission #548055

#	Time	Username	Problem	Language	Result	Execution time	Memory
548055		SamNguyen	Gap (APIO16_gap)	C++14	16.22 / 100	68 ms	2240 KiB

gap

#include "gap.h"
#include <vector>
#include <iostream>
#include <random>
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 {
	vector<long long> ans;

	void solve(long long MIN, long long MAX) {
		if (MIN > MAX) 
			return;

		long long L, R;
		MinMax(MIN, MAX, &L, &R);

		if (L == -1 and R == -1)
			return;

		if (L == R) {
			ans.push_back(L);
			return;
		}

		if (R - L == 1) {
			ans.push_back(L);
			ans.push_back(R);
			return;
		}

		long long M = random(L + 1, R - 1);
		//long long M = (L + R) / 2;

		ans.push_back(L);
		solve(L + 1, M);
		solve(M + 1, R - 1);
		ans.push_back(R);
	}

	long long findGap(int N) {
		solve(0, INF);

		/*
		for (long long e : ans) cerr << e << " ";
		cerr << endl;
		*/

		return calc_cost(ans);
	}
}


long long findGap(int T, int N) {
	//return (T == 1) ? SUB1::findGap(N) : SUB2::findGap(N);
	return SUB2::findGap(N);
}

• Subtask 1: 0 / 30
• Subtask 2: 16.2155448532 / 70