Submission #116763

#	Time	Username	Problem	Language	Result	Execution time	Memory
116763		roseanne_pcy	Three Friends (BOI14_friends)	C++14	100 / 100	51 ms	5368 KiB

friends

#include <bits/stdc++.h>
using namespace std;
#define X first
#define Y second
#define pb push_back
#define mp make_pair
typedef pair<int, int> ii;
typedef vector<int> vi;
typedef vector< ii > vii;
typedef long long L;
typedef vector< L > vL;
typedef vector< vL > vvL;
typedef vector< vi > vvi;
typedef vector< vii > vvii;
const int inf = 1e9;
const L inf8 = 1e18;
const int maxn = 2e6 + 5;
const int md = 1e9 + 7;
void np()
{
	puts("NOT POSSIBLE"); exit(0);
}
void nu()
{
	puts("NOT UNIQUE"); exit(0);
}
char s[maxn];
int main()
{
	int n; scanf("%d", &n);
	scanf("%s", s);
	if(n%2 == 0 || n<= 2) np();
	int a = 0, b = 0;
	int skipped = 0;
	int ptr = n/2;
	bool bad = 0;
	for(int i = 0; i< n/2; i++)
	{
		if(s[i] == s[ptr]) ptr++;
		else if(!skipped)
		{
			skipped = 1;
			i--;
			ptr++;
		}
		else
		{
			bad = 1;
			break;
		}
	}
	if(!bad) a = 1;
	skipped = 0; bad = 0; ptr = 0;
	for(int i = n/2+1; i< n; i++)
	{
		if(s[i] == s[ptr]) ptr++;
		else if(!skipped)
		{
			skipped = 1;
			i--;
			ptr++;
		}
		else
		{
			bad = 1; break;
		}
	}
	bool same = 1;
	for(int i = 0; i< n/2; i++) if(s[i] != s[n/2+i+1]) same = 0;
	if(!bad) b = 1;
	if(a&&b && !same) nu();
	if(a+b == 0) np();
	if(a) for(int i = 0; i< n/2; i++) printf("%c", s[i]);
	else for(int i = n/2+1; i< n; i++) printf("%c", s[i]);
	return 0;
}

Compilation message (stderr)

friends.cpp: In function 'int main()':
friends.cpp:30:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  int n; scanf("%d", &n);
         ~~~~~^~~~~~~~~~
friends.cpp:31:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s", s);
  ~~~~~^~~~~~~~~

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