Submission #216191

#	Time	Username	Problem	Language	Result	Execution time	Memory
216191		Pajaraja	Table Tennis (info1cup20_tabletennis)	C++17	100 / 100	626 ms	5508 KiB

tabletennis

#include <bits/stdc++.h>
#define MAXN 200007
#define MAXK 407
using namespace std;
int a[MAXN],n,k,m;
mt19937 rng(time(NULL));
bool check(int s)
{
	int t1=1,t2=m;
	vector<pair<int,int> > p;
	while(t1<t2)
	{
		if(a[t1]+a[t2]==s) p.push_back({t1,t2});
		if(a[t1]+a[t2]<=s) t1++;
		if(a[t1]+a[t2]>s) t2--;
	}
	if(p.size()<n/2) return false;
	for(int i=0;i<n/2;i++) printf("%d ",a[p[i].first]);
	for(int i=n/2-1;i>=0;i--) printf("%d ",a[p[i].second]);
	return true;
}
int main()
{
	scanf("%d%d",&n,&k); m=n+k;
	for(int i=1;i<=m;i++) scanf("%d",&a[i]);
	if(n>k) 
	{
		bool found=false;
		while(!found)
		{
			int x=rng()%m+1;
			for(int i=max(m+1-x-k,1);i<=min(m+1-x+k,m) && !found;i++) found=check(a[i]+a[x]);
		}
	}
	else
	{
		bool found=false;
		for(int i=1;i<=k+1 && !found;i++) for(int j=m;j>=m-k-1 && !found;j--) found=check(a[i]+a[j]); 
	}
}

Compilation message (stderr)

tabletennis.cpp: In function 'bool check(int)':
tabletennis.cpp:17:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if(p.size()<n/2) return false;
     ~~~~~~~~^~~~
tabletennis.cpp: In function 'int main()':
tabletennis.cpp:24:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&k); m=n+k;
  ~~~~~^~~~~~~~~~~~~~
tabletennis.cpp:25:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=1;i<=m;i++) scanf("%d",&a[i]);
                        ~~~~~^~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 9 / 9
• Subtask 3: 14 / 14
• Subtask 4: 15 / 15
• Subtask 5: 9 / 9
• Subtask 6: 14 / 14
• Subtask 7: 15 / 15
• Subtask 8: 13 / 13