Submission #597474

#	Time	Username	Problem	Language	Result	Execution time	Memory
597474		GusterGoose27	Long Distance Coach (JOI17_coach)	C++11	0 / 100	0 ms	340 KiB

coach

#include <bits/stdc++.h>

using namespace std;

typedef pair<int, int> pii;
typedef long long ll;

const int MAXN = 2e5+1;
ll n, m, t, wint, wcost;
ll dp[MAXN];
pii ppl[MAXN]; // time, drop_cost
ll refill[MAXN];
int stat_with[MAXN];
ll pre[MAXN];
const ll inf = 4e18;

class Frac {
public:
	ll num, denom;
	Frac() {
		num = inf;
		denom = 1;
	}
	Frac(ll x, ll y) {
		num = x;
		denom = y;
		reduce();
	}
	void reduce() {
		if (denom < 0) {
			denom *= -1;
			num *= -1;
		}
		ll g = gcd(abs(num), denom);
		num /= g;
		denom /= g;
	}
	ll gcd(ll a, ll b) {
		if (a > b) return gcd(b, a);
		if (a == 0) return b;
		return gcd(b%a, a);
	}
};

bool operator<(Frac a, Frac b) {
	return a.num*b.denom < b.num*a.denom;
}

class Line {
public:
	ll inter;
	ll slope;
	Frac rbound;
	Line(ll in, ll s) {
		inter = in;
		slope = s;
	}
};

Frac intersect(Line a, Line b) {
	return Frac(a.inter-b.inter, b.slope-a.slope);
}

int main() {
	ios_base::sync_with_stdio(false); cin.tie(NULL);
	cin >> t >> m >> n >> wcost >> wint;
	m++;
	for (int i = 0; i < m-1; i++) cin >> refill[i];
	refill[m-1] = t;
	n++;
	ppl[0] = pii(0, 0);
	for (int i = 1; i < n; i++) {
		int x, y; cin >> x >> y;
		ppl[i] = pii(x, y);
	}
	sort(ppl, ppl+n);
	fill(stat_with, stat_with+n, -1);
	ll cur = 0;
	for (int i = 0; i < n; i++) {
		cur += ppl[i].second;
		pre[i] = cur;
	}
	for (int i = 0; i < m; i++) {
		ll comp = refill[i]/wint;
		int mn = 0;
		int mx = n;
		while (mx > mn+1) {
			ll cur = (mn+mx)/2;
			if ((refill[i]-ppl[cur].first)/wint == comp) mn = cur;
			else mx = cur;
		}
		if (stat_with[mn] == -1) stat_with[mn] = i;
	}
	dp[0] = wcost*(t/wint+1);
	vector<Line> hull;
	hull.push_back(Line(dp[0]-pre[0], 0));
	for (int i = 1; i < n; i++) {
		dp[i] = wcost*((t-ppl[i].first)/wint+1)+dp[i-1];
		if (stat_with[i] >= 0) {
			int stat = stat_with[i];
			ll sl = wcost*((refill[stat]-ppl[i].first)/wint);
			int mn = -1;
			int mx = hull.size()-1;
			Frac f(sl, 1);
			while (mx > mn+1) {
				int cur = (mn+mx)/2;
				if (hull[cur].rbound < f) mn = cur;
				else mx = cur;
			}
			ll cval = pre[i]+hull[mx].inter+hull[mx].slope*sl+i*sl;
			dp[i] = min(dp[i], cval);
		}
		Line cur_l(dp[i]-pre[i], -i);
		Frac inter = intersect(cur_l, hull.back());
		while (hull.size() > 1 && inter < hull[hull.size()-2].rbound) {
			hull.pop_back();
			inter = intersect(cur_l, hull.back());
		}
		hull.back().rbound = inter;
		hull.push_back(cur_l);
	}
	cout << dp[n-1] << "\n";
}

• Subtask 1: 0 / 16
• Subtask 2: 0 / 30
• Subtask 3: 0 / 25
• Subtask 4: 0 / 29