Submission #1078973

#	Time	Username	Problem	Language	Result	Execution time	Memory
1078973		UmairAhmadMirza	Carnival Tickets (IOI20_tickets)	C++17	27 / 100	440 ms	73040 KiB

tickets

#include <bits/stdc++.h>
using namespace std;
#define ll long long
int const N=1505;
bool od[N];
bool temp[N];
void allocate_tickets(vector<vector<int>> _x);

ll fun(ll val,vector<pair<int,int>> &pr){
	int n=pr.size();
	int lw=n/2,hg=n/2;
	ll ans=0;
	vector<pair<ll,int>> diff;
	for(int i=0;i<n;i++){
		auto [mn,mx]=pr[i];
		if(mx<=val){
			lw--;
			ans+=val-mn;
		}
		else if(mn>val){
			hg--;
			ans+=mx-val;
			temp[i]=1;
		}
		else{
			ans+=mx-val;
			diff.push_back({((mx-val)-(val-mn)),i});
		}
	}
	if(hg<0 || lw<0 || hg+lw!=diff.size())
		return -1;
	// cout<<ans<<endl;
	// cout<<lw<<' '<<hg<<endl;
	sort(diff.begin(),diff.end());
	// for(int i=0;i<diff.size();i++){
	// 	cout<<diff[i].first<<' '<<diff[i].second<<endl;
	// }
	for(int i=0;i<lw;i++)
		ans+=-diff[i].first;
	reverse(diff.begin(),diff.end());
	for(int i=0;i<hg;i++){
		// ans+=max(0LL,diff[i].first);
		temp[diff[i].second]=1;
	}
	return ans;
}

ll yep_round(vector<pair<int,int>> &pr){
	int n=pr.size();
	for (int i = 0; i < n; ++i){
		od[i]=0;
		temp[i]=0;
	}
	ll cur=0;
	vector<int> all;
	for(auto [x,y]:pr){
		all.push_back(x);
		all.push_back(y-1);
	}
	for(int i:all){
		for(int j=0;j<n;j++)
			temp[j]=0;
		ll c=fun(i,pr);
		// cout<<endl;
		// cout<<i<<' '<<c<<endl;
		// for(int j=0;j<n;j++)
		// 	cout<<temp[j]<<' ';
		// cout<<endl;
		if(c>=cur){
			cur=c;
			for(int j=0;j<n;j++)
				od[j]=temp[j];
		}
	}
	vector<int> v;
	cur=0;
	for(int i=0;i<n;i++){
		if(od[i])
			v.push_back(pr[i].second);
		else
			v.push_back(pr[i].first);
	}
	sort(v.begin(),v.end());
	for(int i=0;i<n;i++)
		cur+=abs(v[n/2]-v[i]);
	// cout<<cur<<endl;
	return cur;
}

long long find_maximum(int k, vector<vector<int>> d){
	vector<int> all;
	int n=d.size();
	int m=d[0].size();
	vector<vector<int>> x=d;
	for(int i=0;i<n;i++)
		for(int j=0;j<m;j++)
			x[i][j]=-1;
	ll ans=0;
	int p1[n],p2[n];
	for(int i=0;i<n;i++){
		p1[i]=0;
		p2[i]=m-1;
	}
	for(int r=0;r<k;r++){
		vector<pair<int,int>> pr;
		for(int i=0;i<n;i++)
			pr.push_back({d[i][p1[i]],d[i][p2[i]]});
		ans+=yep_round(pr);
		for(int i=0;i<n;i++){
			if(od[i]){
				x[i][p2[i]]=r;
				p2[i]--;
			}
			else{
				x[i][p1[i]]=r;
				p1[i]++;
			}
		}
	}
	allocate_tickets(x);
	return ans;
}

Compilation message (stderr)

tickets.cpp: In function 'long long int fun(long long int, std::vector<std::pair<int, int> >&)':
tickets.cpp:30:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |  if(hg<0 || lw<0 || hg+lw!=diff.size())
      |                     ~~~~~^~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 16 / 16
• Subtask 3: 0 / 14
• Subtask 4: 0 / 14
• Subtask 5: 0 / 12
• Subtask 6: 0 / 23
• Subtask 7: 0 / 10