Submission #127515

#	Time	Username	Problem	Language	Result	Execution time	Memory
127515		TadijaSebez	Three Friends (BOI14_friends)	C++11	100 / 100	60 ms	5240 KiB

friends

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
const int N=2000050;
char s[N];
int main()
{
	int n,A=0,B=0,C=0,D=0;
	scanf("%i",&n);
	scanf("%s",s+1);
	if(n%2==0) return 0*printf("NOT POSSIBLE\n");
	int x=(n+1)/2,y=x+1,z=x-1;
	while(s[A+1]==s[A+x]) A++;
	while(s[B+1]==s[B+y]) B++;
	while(s[n-C]==s[x-C]) C++;
	while(s[n-D]==s[z-D]) D++;
	//printf("%i %i %i %i\n",A,B,C,D);
	vector<int> ans;
	int hal=n/2;
	if(B>=hal)
	{
		ans.pb(x);
	}
	else
	{
		if(B+C>=hal) ans.pb(1);
		if(A+D>=hal) ans.pb(n);
		/*for(int i=1;i<x;i++)
		{
			if(B>=i-1 && C>=x-i){ ans.pb(i);break;}
		}
		for(int i=x+1;i<=n;i++)
		{
			if(A>=i-x && D>=n-i){ ans.pb(i);break;}
		}*/
	}
	if(ans.empty()) printf("NOT POSSIBLE\n");
	else if(ans.size()>1) printf("NOT UNIQUE\n");
	else
	{
		//printf("%i\n",ans[0]);
		if(ans[0]<=x) for(int i=x+1;i<=n;i++) printf("%c",s[i]);
		else for(int i=1;i<x;i++) printf("%c",s[i]);
		printf("\n");
	}
	return 0;
}

Compilation message (stderr)

friends.cpp: In function 'int main()':
friends.cpp:9:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%i",&n);
  ~~~~~^~~~~~~~~
friends.cpp:10:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s",s+1);
  ~~~~~^~~~~~~~~~

• Subtask 1: 35 / 35
• Subtask 2: 65 / 65