Submission #936334

#	Time	Username	Problem	Language	Result	Execution time	Memory
936334		8pete8	Schools (IZhO13_school)	C++17	100 / 100	87 ms	17468 KiB

school

#include<iostream>
#include<stack>
#include<map>
#include<vector>
#include<string>
#include<unordered_map>
#include <queue>
#include<cstring>
#include<cassert>
#include<limits.h>
#include<cmath>
#include<set>
#include<numeric> //gcd(a,b)
#include<algorithm>
#include<bitset> 
#include<stack>
using namespace std;
#define ll long long
#define f first
#define endl "\n"
#define s second
#define pii pair<int,int>
#define pppiiii pair<pii,pii>
#define ppii pair<int,pii>
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define pb push_back
//#define mp make_pair
#define lb lower_bound
#define ub upper_bound
#define fastio ios::sync_with_stdio(false);cin.tie(NULL);
#pragma GCC optimize ("03,unroll-loops")
#define int long long
const int mod=1e9+7,mxn=3e5,inf=1e18,minf=-1e18,Mxn=2e6,lg=17;
void setIO(string name){
	ios_base::sync_with_stdio(0); cin.tie(0);		
	freopen((name+".in").c_str(),"r",stdin);		
	freopen((name+".out").c_str(),"w",stdout);	
}	
int del[mxn+10];
int32_t main(){
	fastio
	int n,a,b;cin>>n>>a>>b;
	int ans=0;
	vector<pii>v(n);
	for(int i=0;i<n;i++)cin>>v[i].f>>v[i].s;
	sort(rall(v));
	v.pb({0,0});
	int cur=0;
	priority_queue<pii>q1,q2;
	while(cur<min(n,a)){
		ans+=v[cur].f;
		q1.push({v[cur].s-v[cur].f,cur});
		cur++;
	}
	for(int i=cur;i<n;i++)q2.push({v[i].s,i});
	for(int i=0;i<b;i++){
		int cost1=minf,cost2=minf;
		while(!q2.empty()&&q2.top().s<cur)q2.pop();
		while(!q1.empty()&&del[q1.top().s])q1.pop();
		while(cur<n&&del[cur])cur++;
		if(!q1.empty())cost1=q1.top().f+v[cur].f;
		if(!q2.empty())cost2=q2.top().f;
		if(cost1<=0&&cost2<=0)break;
		if(cost1>cost2){
			q1.pop();
			ans+=cost1;
			if(cur<n)q1.push({v[cur].s-v[cur].f,cur}),cur++;
		}
		else{
			del[q2.top().s]=1;
			ans+=cost2;
			q2.pop();
			
		}
	}
	cout<<ans;
}
/*
we take the first m best cities
then we need to take s more
if s is outside the set
then we can just take the s
or else we can s-m+the current top m that is left
the current top m->a constant
sort (s-m)? then greedy take m then greedy swap to s?
problems{
	sorting by s-m->but the in set and not in set will also affected
	so if in the set the cost of change would be curtopm+s-m{
		this will also make the curtopm be in set m
		which we can changed later?
	}
	if not the cost of change would be s
}
if we take b we cant change it back?
*/

Compilation message (stderr)

school.cpp: In function 'void setIO(std::string)':
school.cpp:37:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |  freopen((name+".in").c_str(),"r",stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
school.cpp:38:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |  freopen((name+".out").c_str(),"w",stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100