Submission #958951

#	Time	Username	Problem	Language	Result	Execution time	Memory
958951		MinaRagy06	Shortcut (IOI16_shortcut)	C++17	71 / 100	2025 ms	2516 KiB

shortcut

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#include "shortcut.h"
#ifdef MINA
#include "grader.cpp"
#endif
using namespace std;
#define ll long long

const int N = 3005;
ll find_shortcut(int n, vector<int> l, vector<int> a, int c) {
	reverse(l.begin(), l.end()), l.push_back(0), reverse(l.begin(), l.end()), l.push_back(0);
	reverse(a.begin(), a.end()), a.push_back(-1), reverse(a.begin(), a.end());
	ll prf[n + 2]{};
	for (int i = 2; i <= n; i++) {
		prf[i] = prf[i - 1] + l[i - 1];
	}
	ll s[n + 2]{}, d[n + 2]{};
	for (int i = 1; i <= n; i++) {
		s[i] = prf[i] + a[i];
		d[i] = prf[i] - a[i];
	}
	auto check = [&] (ll t) {
		ll l1 = -1e18, r1 = 1e18, l2 = -1e18, r2 = 1e18;
		for (int i = 1; i <= n; i++) {
			for (int j = i + 1; j <= n; j++) {
				if (i == j) continue;
				if (prf[j] - prf[i] + a[i] + a[j] > t) {
					l1 = max(l1, s[i] + s[j] - t + c);
					r1 = min(r1, d[i] + d[j] + t - c);
					l2 = max(l2, - d[i] + s[j] - t + c);
					r2 = min(r2, - s[i] + d[j] + t - c);
				}
			}
		}
		for (int x = 1; x <= n; x++) {
			ll st = max(l1 - prf[x], l2 + prf[x]);
			ll en = min(r1 - prf[x], r2 + prf[x]);
			for (int y = 1; y <= n; y++) {
				if (st <= prf[y] && prf[y] <= en) {
					return true;
				}
			}
		}
		return false;
	};
	ll st = 0, en = 1ll << 41;
	while (st <= en) {
		ll md = (st + en) >> 1;
		if (check(md)) {
			en = md - 1;
		} else {
			st = md + 1;
		}
	}
	return st;
}

• Subtask 1: 9 / 9
• Subtask 2: 14 / 14
• Subtask 3: 8 / 8
• Subtask 4: 7 / 7
• Subtask 5: 33 / 33
• Subtask 6: 0 / 22
• Subtask 7: 0 / 4
• Subtask 8: 0 / 3