Submission #423467

#	Time	Username	Problem	Language	Result	Execution time	Memory
423467		victoriad	Three Friends (BOI14_friends)	C++14	100 / 100	55 ms	8204 KiB

friends

#include <cmath>
#include <cstdio>
#include <iostream>
#include <algorithm>
#include <utility>
#include <vector>
#include <map>
using namespace std;
int main(){
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	int n;
	string s;
	cin>>n>>s;
	vector<int>can(30,0);
	if(n%2==0){
		cout<<"NOT POSSIBLE";
	}
	else{
		for(int i=0;i<n;i++){
			can[s[i]-65]++;
		}
		int l=0;
		int us=-1;
		vector<char> a;
		int x,y;
		int p=-1;
		for(int i=0;i<n/2;i++){
			if(s[i]==s[i+n/2]||s[i]==s[i+n/2+1]){
				a.push_back(s[i]);
				if(s[i]==s[i+1]&& s[i]!=s[i+n/2]&& s[i+n/2+1]!=s[i+n/2+2]){
					a.pop_back();
					l++;
				}
			}
			else{
				if(l==0){
					l=1;
					p=i;
				}
				else{
					l++;
					cout<<"NOT POSSIBLE";
					break;
				}
			}
		}
		if(l<=1){
		if(s[n/2]!=s[0] && s[n/2]==s[n-1])a.push_back(s[n/2]);
		if(a.size()!=n/2)cout<<"NOT POSSIBLE";
		else{
		vector<char>b;
		if(l==0){
			for(int i=1;i<=n/2;i++){
				if(s[i]==s[i+n/2])b.push_back(s[i]);
				else{
					break;
				}
			}
		}
		bool j=true;
		if(b.size()==a.size()){
			for(int i=0;i<n/2;i++){
				if(a[i]!=b[i]){
					j=false;
					cout<<"NOT UNIQUE";
					break;
				}
			}
		}
		if(j){
			for(int i=0;i<n/2;i++)cout<<a[i];
		}
		}
		}
	}
	return 0;
}

Compilation message (stderr)

friends.cpp: In function 'int main()':
friends.cpp:50:14: warning: comparison of integer expressions of different signedness: 'std::vector<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   50 |   if(a.size()!=n/2)cout<<"NOT POSSIBLE";
      |      ~~~~~~~~^~~~~
friends.cpp:24:7: warning: unused variable 'us' [-Wunused-variable]
   24 |   int us=-1;
      |       ^~
friends.cpp:26:7: warning: unused variable 'x' [-Wunused-variable]
   26 |   int x,y;
      |       ^
friends.cpp:26:9: warning: unused variable 'y' [-Wunused-variable]
   26 |   int x,y;
      |         ^
friends.cpp:27:7: warning: variable 'p' set but not used [-Wunused-but-set-variable]
   27 |   int p=-1;
      |       ^

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