Submission #107564

#	Time	Username	Problem	Language	Result	Execution time	Memory
107564		patrikpavic2	Three Friends (BOI14_friends)	C++17	100 / 100	69 ms	6136 KiB

friends

#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <ctime>
#include <algorithm>
#include <set>
#include <vector>
#include <queue>
#include <map>

#define X first
#define Y second
#define PB push_back

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair < int, int > pii;
typedef vector < int > vi;
typedef set < int > si;

const int N = 1e5 + 500;
const int M = 1e6 + 500;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
const int OFF = (1 << 18);
const int LOG = 20;
const double EPS = 1e-9;
const double PI = 3.1415926535;

char s[2 * M], ans[2 * M];
int cnt, n, can = 0;

int main(){
    scanf("%d", &n);
    if(n % 2 == 0){
        printf("NOT POSSIBLE\n");
        return 0;
    }
    scanf("%s", s);
    int j = n / 2;
    for(int i = 0;2 * i + 1 < n;i++,j++){
        if(s[i] != s[j]) cnt++,i--;
        if(cnt > 1) break;
    }
    if(cnt <= 1){
        for(int i = 0;2 * i + 1 < n;i++)
            ans[i] = s[i];
        can++;
    }
    cnt = 0;j = 0;
    for(int i = n / 2 + 1;i < n;i++,j++){
        if(s[i] != s[j]) cnt++,i--;
        if(cnt > 1) break;
    }
    if(cnt <= 1){
        for(int i = n / 2 + 1;i < n;i++){
            if(ans[i - n / 2  - 1] != s[i] && can){
                printf("NOT UNIQUE\n");
                return 0;
            }
            ans[i - n / 2  - 1] = s[i];
        }
        can++;
    }

    if(!can) printf("NOT POSSIBLE\n");
    else{
        for(int i = 0;2 * i + 1 < n;i++)
            printf("%c", ans[i]);
        printf("\n");
    }
    return 0;
}

Compilation message (stderr)

friends.cpp: In function 'int main()':
friends.cpp:36:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
friends.cpp:41:10: 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