Submission #54329

#	Time	Username	Problem	Language	Result	Execution time	Memory
54329		ksun48	Long Distance Coach (JOI17_coach)	C++14	71 / 100	2051 ms	14240 KiB

coach

#include <bits/stdc++.h>
typedef long long LL;
using namespace std;

LL cnt(LL m, LL a, LL b, LL T){
	a -= m;
	b -= m;
	if(b < 0) return 0;
	a = max(a, 0LL);
	b = max(b, 0LL);
	LL f = (a+T-1)/T;
	LL g = (b)/T;
	return max(g-f+1, 0LL);
}

int main(){
	cin.sync_with_stdio(0); cin.tie(0);
	LL X, N, M, W, T;
	cin >> X >> N >> M >> W >> T;
	T *= 2;
	X *= 2;
	// X = total duration
	// N = # stops
	// M = # passenges
	vector<LL> stop;
	stop.push_back(0);
	for(LL i = 0; i < N; i++){
		LL s;
		cin >> s;
		s *= 2;
		stop.push_back(s);
	}
	stop.push_back(X);

	// W = cost
	vector<pair<LL,LL> > times;

	LL totalrefundcost = 0;
	for(LL i = 0; i < M; i++){
		LL d, c;
		cin >> d >> c;
		d *= 2;
		totalrefundcost += c;
		if(X < (X/T) * T + d){
			c += W;
			stop.push_back((X/T) * T + d + 1);
		}
		times.push_back({d,c});
	}
	sort(times.begin(), times.end());
	sort(stop.begin(), stop.end());
	X = ((X/T) + 1) * T - 1;

	vector<LL> t;
	vector<LL> refundcost;
	t.push_back(0);
	refundcost.push_back(0); // but you must always feed the driver
	for(int i = 0; i < times.size(); i++){
		t.push_back(times[i].first);
		refundcost.push_back(times[i].second);
	}
	t.push_back(T);
	refundcost.push_back(0); // should not use this result

	// ^ preprocessing

	vector<LL> dp(refundcost.size(), W*(X+1));
	dp[0] = 0;
	vector<LL> minstopindex(refundcost.size(), stop.size());
	//vector<LL> minconst(refundcost.size(), W * cnt(t[i], 0, X, T));
	for(LL r = 1; r < stop.size(); r++){
		LL R = stop[r];
		for(int i = 0; i < t.size(); i++){
			if(t[i] < (R % T) && (R % T) < t[i+1]){
				minstopindex[i] = min(minstopindex[i], r);
				break;
			}
		}
	}
	for(int j = 1; j < refundcost.size(); j++){
		LL cost = 0;
		LL idx = stop.size();
		for(int i = j-1; i >= 0; i--){
			dp[j] = min(dp[j], dp[i] + W * cnt(t[i], 0, X, T) + cost - refundcost[i]);
			idx = min(idx, minstopindex[i]);
			if(idx == stop.size()){
				cost += W * cnt(t[0], 0, X, T);
			} else {
				cost += W * (cnt(t[i], 0, stop[idx], T) - 1);
			}
		}
	}
	// T = time delay
	cout << dp[refundcost.size()-1] + totalrefundcost << '\n';
}

Compilation message (stderr)

coach.cpp: In function 'int main()':
coach.cpp:58:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < times.size(); i++){
                 ~~^~~~~~~~~~~~~~
coach.cpp:71:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(LL r = 1; r < stop.size(); r++){
                ~~^~~~~~~~~~~~~
coach.cpp:73:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 0; i < t.size(); i++){
                  ~~^~~~~~~~~~
coach.cpp:80:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int j = 1; j < refundcost.size(); j++){
                 ~~^~~~~~~~~~~~~~~~~~~
coach.cpp:86:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if(idx == stop.size()){
       ~~~~^~~~~~~~~~~~~~

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