Submission #870862

#	Time	Username	Problem	Language	Result	Execution time	Memory
870862		pcc	Discharging (NOI20_discharging)	C++14	100 / 100	86 ms	25108 KiB

Discharging

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

#define ll long long
#define int ll
#define pll pair<ll,ll>
#define pii pair<int,int>
#define fs first
#define sc second
#define tlll tuple<ll,ll,ll>


const ll mxn = 1e6+10;
vector<pll> v;
ll sum[mxn],dp;
deque<pll> dq;
int n;
ll total = 0;

inline ll calc(pll line,ll val){
	return line.fs*val+line.sc;
}
inline bool out(pll a,pll b,pll c){
	return (a.sc-b.sc)*(c.fs-b.fs)>=(b.sc-c.sc)*(b.fs-a.fs);
}

main(){
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin>>n;
	for(int i = 0;i<n;i++){
		int k;
		cin>>k;
		if(v.empty()||v.back().fs < k)v.push_back({k,1});
		else v.back().sc++;
	}
	dq.push_back(make_pair(0ll,0ll));
	sum[0] = v[0].sc;
	for(int i = 1;i<v.size();i++){
		sum[i] = sum[i-1]+v[i].sc;
	}
	for(int i = 0;i<v.size();i++){
		pll p = v[i];
		while(dq.size()>1&&calc(dq[1],p.fs)<=calc(dq[0],p.fs))dq.pop_front();
		dp = p.fs*n+calc(dq.front(),p.fs);
		pll now = make_pair(-sum[i],dp);
		while(dq.size()>1&&out(dq.end()[-2],dq.end()[-1],now))dq.pop_back();
		dq.push_back(make_pair(-sum[i],dp));
	}
	cout<<dp;
}

Compilation message (stderr)

Discharging.cpp:27:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   27 | main(){
      | ^~~~
Discharging.cpp: In function 'int main()':
Discharging.cpp:38:17: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |  for(int i = 1;i<v.size();i++){
      |                ~^~~~~~~~~
Discharging.cpp:41:17: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |  for(int i = 0;i<v.size();i++){
      |                ~^~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 13 / 13
• Subtask 3: 25 / 25
• Subtask 4: 11 / 11
• Subtask 5: 14 / 14
• Subtask 6: 28 / 28