Submission #787495

#	Time	Username	Problem	Language	Result	Execution time	Memory
787495		Sohsoh84	Shortcut (IOI16_shortcut)	C++17	0 / 100	1 ms	340 KiB

shortcut

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

using namespace std;

typedef long long ll;

#define sep		' '
#define debug(x)	cerr << #x << ": " << x << endl; 

const ll MAXN = 1e6 + 10;
const ll INF = 8e18;

int n;
ll L[MAXN], ps[MAXN], D[MAXN], XT[MAXN], XS[MAXN], c, fans;

inline ll dist(int i, int j) {
	if (i > j) swap(i, j);
	return ps[j] - ps[i];
}

inline ll solve(int l, int r, bool flag = false) {
	assert(r >= l);
	if (r < l) return INF;
	ll ans = 0;
	for (int i = 1; i <= n; i++) {
		for (int j = i + 1; j <= n; j++) {
			ans = max(ans, min(dist(i, j), dist(i, l) + dist(r, j) + c)+ D[i] + D[j]);
		}
	}

	return ans;
}

inline void divide(int l, int r, int optl, int optr) {
	if (r < l) return;
	int mid = (l + r) >> 1;

	int opt = optl;
	ll ans = INF;
	
	for (int i = optl; i <= min(optr, mid); i++) {
		ll tans = solve(i, mid);
		if (tans < ans) {
			opt = i;
			ans = tans;
		}
	}
	
	fans = min(fans, ans);
	divide(l, mid - 1, optl, opt);
	divide(mid + 1, r, opt, optr);
}

ll find_shortcut(int n_, vector<int> l_, vector<int> d_, int c_) {
	n = n_;
	c = c_;
	for (int i = 1; i <= n; i++) {
		L[i] = l_[i - 1];
		D[i] = d_[i - 1];
		if (i < n) ps[i + 1] = ps[i] + L[i];

		XS[i] = D[i] - ps[i];
		XT[i] = D[i] + ps[i];
	}

	fans = solve(1, 1, 1);
	divide(1, n, 1, n);
	return fans;
}

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