Submission #151657

#	Time	Username	Problem	Language	Result	Execution time	Memory
151657		qkxwsm	Shortcut (IOI16_shortcut)	C++14	93 / 100	2058 ms	24332 KiB

shortcut

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

using namespace std;

template<class T, class U>
void ckmin(T &a, U b)
{
	if (a > b) a = b;
}
template<class T, class U>
void ckmax(T &a, U b)
{
	if (a < b) a = b;
}

#define y1 qwertyuiop
#define y2 asdfghjkl
#define MP make_pair
#define PB push_back
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define FOR(i, a, b) for (auto i = (a); i < (b); i++)
#define FORD(i, a, b) for (auto i = (a) - 1; i >= (b); i--)
#define SZ(x) ((int) ((x).size()))
#define ALL(x) (x).begin(), (x).end()
#define MAXN 1000013
#define INF 1000000007
#define LLINF 2696969696969696969ll

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pii> vpi;
typedef vector<pll> vpl;

int N;
ll D;
pll arr[MAXN];
vl pts;
int ind[MAXN];
ll fen[2][MAXN];

bool check(ll s)
{
	pll x = {-LLINF, LLINF}, y = {-LLINF, LLINF};
	FOR(i, 0, SZ(pts) + 1)
	{
		fen[0][i] = LLINF; fen[1][i] = -LLINF;
	}
	FOR(i, 0, N)
	{
		ll c = arr[i].fi, d = arr[i].se;
	 	int idx = LB(ALL(pts), c + d - s) - pts.begin() - 1;
		ll mx = -LLINF, mn = LLINF;
		for (int e = idx + 1; e; e -= e & (-e))
		{
			ckmax(mx, fen[1][e]);
			ckmin(mn, fen[0][e]);
		}
		ckmax(x.fi, mx + c + d); ckmin(x.se, mn + c - d);
		ckmax(y.fi, mx - c + d); ckmin(y.se, mn - c - d);
		idx = ind[i];
		for (int e = idx + 1; e <= SZ(pts); e += e & (-e))
		{
			ckmax(fen[1][e], c + d);
			ckmin(fen[0][e], c - d);
		}
	}
	x.fi += (D - s); x.se += (s - D);
	y.fi += (D - s); y.se += (s - D);
	FORD(i, N, 0)
	{
		ll m = arr[i].fi;
		ll lt = max(x.fi - m, m - y.se), rt = min(x.se - m, m - y.fi);
		int idx = LB(arr + i + 1, arr + N, MP(lt, -LLINF)) - arr;
		if (i < idx && idx < N && arr[idx].fi <= rt) return true;
	}
	return false;
}
ll find_shortcut(int n, vi l, vi d, int vs)
{
	N = n; D = vs;
	l.insert(l.begin(), 0);
	FOR(i, 0, N)
	{
		arr[i].fi = l[i];
		arr[i].se = d[i];
	}
	FOR(i, 1, N)
	{
		arr[i].fi += arr[i - 1].fi;
	}
	FOR(i, 0, N)
	{
		pts.PB(arr[i].fi - arr[i].se);
	}
	sort(ALL(pts));
	pts.erase(unique(ALL(pts)), pts.end());
	FOR(i, 0, N)
	{
		ind[i] = LB(ALL(pts), arr[i].fi - arr[i].se) - pts.begin();
	}
	ll lo = 0, hi = (1ll << 50);
	while(hi > lo)
	{
		ll mid = (hi + lo) >> 1;
		if (check(mid)) hi = mid;
		else lo = mid + 1;
	}
    return lo;
}

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