Submission #1078920

#	Time	Username	Problem	Language	Result	Execution time	Memory
1078920		UmairAhmadMirza	Carnival Tickets (IOI20_tickets)	C++17	27 / 100	442 ms	68064 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+=min(mx-val,val-mn);
				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+=max(0LL,-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:30:27: 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