Submission #113121

#	Time	Username	Problem	Language	Result	Execution time	Memory
113121		Bruteforceman	Long Distance Coach (JOI17_coach)	C++11	100 / 100	214 ms	28084 KiB

coach

#include "bits/stdc++.h"
using namespace std;
long long s[200010];
long long d[200010];
long long c[200010];
int N, M;
long long X, W, T;
typedef pair <long long, int> pii;
vector <pii> v;
long long dp[400010];
long long p[400010];
int cnt[400010];


struct CHT {
	vector <long long> M, C;
	bool bad(int i, int j, int k) {
		return (C[k] - C[j]) * (M[i] - M[j]) <= (C[j] - C[i]) * (M[j] - M[k]);
	}
	void add_line(long long m, long long c) {
		if(!M.empty() && M.back() == m) {
			if(C.back() < c) return ;
			else {
				M.pop_back();
				C.pop_back();
			}
		}
		M.push_back(m);
		C.push_back(c);
		while(M.size() >= 3 && bad(M.size() - 3, M.size() - 2, M.size() - 1)) {
			M.erase(M.end() - 2);
			C.erase(C.end() - 2);
		}
	}
	long long search(int b, int e, long long val) {
		if(b == e) {
			return M[b] * val + C[b];
		}
		int mid = (b + e) >> 1;
		if((M[mid] * val + C[mid]) >= (M[mid + 1] * val + C[mid + 1])) {
			return search(mid + 1, e, val);
		} else {
			return search(b, mid, val);
		}
	}
	long long eval(long long x) {
		return search(0, M.size() - 1, x);
	}
} cht;

int main(int argc, char const *argv[])
{
	scanf("%lld %d %d %lld %lld", &X, &N, &M, &W, &T);
	for(int i = 1; i <= N; i++) {
		scanf("%lld", &s[i]);
	}
	s[++N] = X;
	for(int i = 1; i <= N; i++) {
		v.push_back(pii(s[i] % T, i));
	}  
	for(int i = 1; i <= M; i++) {
		scanf("%lld %lld", &d[i], &c[i]);
		v.push_back(pii(d[i], -i));
	}
	sort(v.begin(), v.end());

	long long ans = (X / T) + 1;
	for(int i = 1; i <= M; i++) {
		ans += 1 + ((X - d[i]) / T);
	}
	ans *= W;
	int sz = N + M;
	v.insert(v.begin(), pii(0, 0));


	for(int i = 1; i <= sz; i++) {
		if(v[i].second < 0) {
			int id = -v[i].second;
			p[i] = c[id] - W * (1 + ((X - d[id]) / T));
			cnt[i] = 1;
		}
		p[i] += p[i - 1];
		cnt[i] += cnt[i - 1];
	}

	cht.add_line(0, 0);

	dp[0] = 0;
	for(int i = 1; i <= sz; i++) {
		if(v[i].second < 0) {
			dp[i] = dp[i - 1];
		} else {
			long long var = W * (s[v[i].second] / T);
			long long cost = 0;
			long long add = p[i] + var * cnt[i];
			dp[i] = add + cht.eval(var);
		}
		long long m = -cnt[i];
		long long c = dp[i] - p[i];
		cht.add_line(m, c);
	}
	ans += dp[sz];
	printf("%lld\n", ans);
	return 0;
}

Compilation message (stderr)

coach.cpp: In function 'int main(int, const char**)':
coach.cpp:94:14: warning: unused variable 'cost' [-Wunused-variable]
    long long cost = 0;
              ^~~~
coach.cpp:53:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld %d %d %lld %lld", &X, &N, &M, &W, &T);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
coach.cpp:55:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld", &s[i]);
   ~~~~~^~~~~~~~~~~~~~~
coach.cpp:62:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld %lld", &d[i], &c[i]);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

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