Submission #54989

#	Time	Username	Problem	Language	Result	Execution time	Memory
54989		cki86201	Three Friends (BOI14_friends)	C++11	100 / 100	34 ms	26684 KiB

friends

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>
#include <math.h>
#include <assert.h>
#include <queue>
#include <map>
#include <set>
#include <string>
#include <algorithm>
#include <iostream>
#include <functional>
#include <unordered_map>
#include <unordered_set>
#include <list>
#include <bitset>
#include <complex.h>

using namespace std;
typedef pair<int, int> pii;
typedef long long ll;
#define Fi first
#define Se second
#define pb(x) push_back(x)
#define szz(x) ((int)(x).size())
#define rep(i, n) for(int i=0;i<n;i++)
#define all(x) (x).begin(), (x).end()
typedef tuple<int, int, int> t3;
typedef pair<ll, ll> pll;
typedef long double ldouble;
typedef pair<double, double> pdd;

int N;
char S[2000020];
char T1[2000020];
char T2[2000020];

void solve(){
	scanf("%d", &N);
	scanf("%s", S+1);
	if(N % 2 == 0) { puts("NOT POSSIBLE"); return; }
	for(int i=1;i<=N-1;i++) {
		if(i <= N / 2) T1[i] = S[i];
		else T1[i] = S[i - N/2];
	}
	int ok = 3;
	int f1 = -1;
	for(int i=1;i<=N-1;i++) if(S[i] != T1[i]) { f1 = i; break; }
	if(f1 != -1) {
		for(int i=f1+1;i<=N;i++) if(S[i] != T1[i-1]) { ok ^= 1; break; }
	}
	for(int i=N;i>N-N/2;i--) T2[i-1] = S[i];
	for(int i=N/2;i;i--) T2[i] = T2[i+N/2];
	f1 = -1;
	for(int i=1;i<=N-1;i++) if(S[i] != T2[i]) { f1 = i; break; }
	if(f1 != -1) {
		for(int i=f1+1;i<=N;i++) if(S[i] != T2[i-1]) { ok ^= 2; break; }
	}
	if(ok == 3 && !strcmp(T1+1, T2+1)) ok = 1;
	T1[N/2+1] = T2[N/2+1] = 0;
	if(ok == 0) { puts("NOT POSSIBLE"); return; }
	else if(ok == 1) printf("%s\n", T1+1);
	else if(ok == 2) printf("%s\n", T2+1);
	else puts("NOT UNIQUE");
}

int main(){
	int Tc = 1; // scanf("%d\n", &Tc);
	for(int tc=1;tc<=Tc;tc++){
		solve();
	}
	return 0;
}

Compilation message (stderr)

friends.cpp: In function 'void solve()':
friends.cpp:40:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &N);
  ~~~~~^~~~~~~~~~
friends.cpp:41:7: 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