제출 #1005911

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1005911		omsincoconut	Gap (APIO16_gap)	C++17	48.70 / 100	38 ms	8880 KiB

gap

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

using namespace std;
typedef long long ll;

ll findGap1(int N) {
	ll l = 1, r = N;
	ll fl = LLONG_MIN, fr = LLONG_MAX;
	ll arr[N+1];
	while (l <= r) {
		ll *q1 = new ll(0), *q2 = new ll(0);
		MinMax(fl, fr, q1, q2);
		arr[l++] = *q1;
		arr[r--] = *q2;
		fl = *q1+1;
		fr = *q2-1;
	}
	ll ans = 0;
	for (ll i = 1; i < N; i++) ans = max(ans, arr[i+1] - arr[i]);
	return ans;
}

void query(ll s, ll t, ll &q1, ll &q2) {
	ll *qr1 = new ll(0), *qr2 = new ll(0);
	MinMax(s, t, qr1, qr2);
	q1 = *qr1;
	q2 = *qr2;
}

const ll DV = 5;
void rec(set<ll> &dt, ll l, ll r) {
	if (l > r) return;

	ll q1, q2;
	query(l, r, q1, q2);
	if (q1 == -1) return;

	dt.insert(q1);
	dt.insert(q2);
	ll mid = (q1+q2)/2;
	rec(dt, q1+1, q1 + (q2-q1+1)/DV);
	for (ll i = 1; i < DV-1; i++) rec(dt, q1 + i*(q2-q1+1)/DV + 1, q1 + (i+1)*(q2-q1+1)/DV);
	rec(dt, q1 + (DV-1)*(q2-q1+1)/DV + 1, q2-1);
}

ll findGap2(int N) {
	set<ll> dt;
	rec(dt, -2e18, 2e18);
	vector<ll> arr;
	for (ll i : dt) arr.push_back(i);
	ll ans = 0;
	for (ll i = 0; i < N-1; i++) ans = max(ans, arr[i+1] - arr[i]);
	return ans;
}

ll findGap2_(int N) {
	ll mi, mx;
	query(LLONG_MIN, LLONG_MAX, mi, mx);
	ll ans = (mx-mi+N-2)/(N-1); // by pigeonhole
 
	ll lst = mi, lft = N;
	while (lst < mx && lft > 0) {
		ll q1, q2;
		query(lst+1, lst+ans, q1, q2);
		if (q1 == -1) {
			ll cq1, cq2;
			query(lst+1, mx-1, cq1, cq2);
			if (cq1 == -1) {
				ans = max(ans, mx-lst);
				lst = mx;
				lft = 0;
			} else {
				ans = max({ans, cq1-lst, mx-cq2});
				lst = cq1;
				mx = cq2;
				lft -= 2;
			}
		} else {
			lst = q2;
			lft--;
		}
		if (lft > 1) ans = max(ans, (mx-lst+lft-2)/(lft-1));
	}
	return ans;
}

ll findGap(int T, int N) {
	if (T == 1) return findGap1(N);
	if (N <= 8) return findGap1(N);
	//if (N <= 200) return findGap2_(N);
	return findGap2_(N);
}

컴파일 시 표준 에러 (stderr) 메시지

gap.cpp: In function 'void rec(std::set<long long int>&, ll, ll)':
gap.cpp:41:5: warning: unused variable 'mid' [-Wunused-variable]
   41 |  ll mid = (q1+q2)/2;
      |     ^~~

• Subtask 1: 30 / 30
• Subtask 2: 18.6951166543 / 70