Submission #76833

#	Time	Username	Problem	Language	Result	Execution time	Memory
76833		zetapi	Gift (IZhO18_nicegift)	C++14	0 / 100	2054 ms	117612 KiB

nicegift

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

#define pb  push_back
#define mp  make_pair
#define	int long long
#define itr iterator

typedef pair<int,int> pii;

const int MAX=1e6;

set<pii> st;

set<pii>::itr it_1,it_2;

vector<pii> res;

int N,K,arr[MAX];

void print_1()
{
	assert(!(st.size()%2));
	for(int A=0;A<res.size();A++)
		cout<<res[A].first<<" "<<res[A].second<<" "<<1<<"\n";
	while(!st.empty())
	{
		it_1=st.begin();
		it_2=it_1;
		it_2++;
		cout<<it_1->second<<" "<<it_2->second<<" "<<1<<"\n";
		st.erase(it_1);
		st.erase(it_2);
	}
	return ;
}

void print_3()
{
	vector<pii> vec;
	while(!st.empty())
	{
		it_1=st.begin();
		vec.pb(mp(-1*it_1->first,it_1->second));
		st.erase(it_1);
	}
	assert(vec.size()==3);
	if((vec[0].first+vec[1].first<vec[2].first) or ((vec[0].first+vec[1].first)%2!=vec[2].first%2))
	{
		cout<<-1<<"\n";
		exit(0);
	}
	else
	{
		for(int A=0;A<res.size();A++)
			cout<<res[A].first<<" "<<res[A].second<<" "<<1<<"\n"; 
		while((vec[0].first+vec[1].first)!=vec[2].first)
		{
			cout<<vec[0].second<<" "<<vec[1].second<<" "<<1<<"\n";
			vec[0].first--;
			vec[1].first--;
		}
		assert(vec[0].first+vec[1].first==vec[2].first);
		if(vec[0].first)
			cout<<vec[0].second<<" "<<vec[2].second<<" "<<vec[0].first<<"\n";
		if(vec[1].first)
			cout<<vec[1].second<<" "<<vec[2].second<<" "<<vec[1].first<<"\n";
	}
	return ;
}

signed main()
{
	ios_base::sync_with_stdio(false);

	cin>>N>>K;
	for(int A=1;A<=N;A++)
	{
		cin>>arr[A];
		st.insert(mp(-arr[A],A));
	}
	while(true)
	{
		if(st.size()==3)
		{
			print_3();
			break;
		}
		it_1=st.begin();
		it_2=it_1;
		it_2++;
		pii p=*it_1;
		pii q=*it_2;
		if(p.first==-1)
		{
			print_1();
			break;
		}
		p.first++;
		q.first++;
		st.erase(it_1);
		st.erase(it_2);
		st.insert(p);
		st.insert(q);
		res.pb(mp(p.second,q.second));
	}
	return 0;
}

Compilation message (stderr)

nicegift.cpp: In function 'void print_1()':
nicegift.cpp:24:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int A=0;A<res.size();A++)
              ~^~~~~~~~~~~
nicegift.cpp: In function 'void print_3()':
nicegift.cpp:55:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int A=0;A<res.size();A++)
               ~^~~~~~~~~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 11
• Subtask 3: 0 / 12
• Subtask 4: 0 / 19
• Subtask 5: 0 / 51