Submission #42964

#	Time	Username	Problem	Language	Result	Execution time	Memory
42964		BThero	Three Friends (BOI14_friends)	C++14	0 / 100	11 ms	4796 KiB

friends

#include <assert.h>
#include <stdio.h>

#define pb push_back
#define mp make_pair

#define fi first
#define se second

typedef long long ll;

using namespace std;

char s[2000005];

int n, ans;

void solve() {
    scanf("%d", &n);
    scanf("%s", s);

    if (n % 2 == 0) {
        printf("NOT POSSIBLE\n");
        return;
    }

    assert(n <= 5000);

    int len = (n - 1) / 2;
    ans = -1;

    for (int i = 0; i < n; ++i) {
        int l = 0, r = len;

        if (i == 0) {
            ++l;
        }

        if (i <= r) {
            ++r;
        }

        bool ok = 1;

        while (r < n) {
            if (s[l] != s[r]) {
                ok = 0;
            }

            if (++l == i) {
                ++l;
            }

            if (++r == i) {
                ++r;
            }
        }

        if (ok) {
            if (ans != -1) {
                printf("NOT UNIQUE\n");
                return;
            }

            ans = i;
        }
    }

    if (ans == -1) {
        printf("NOT POSSIBLE\n");
        return;
    }

    for (int i = 0, cnt = 0; cnt < len; ++i) {
        if (i == ans) {
            continue;
        }

        printf("%c", s[i]);
        ++cnt;
    }
}

int main() {
    #ifdef BThero
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #endif // BThero

    int tt = 1;

    while (tt--) {
        solve();
    }

    return 0;
}

Compilation message (stderr)

friends.cpp: In function 'void solve()':
friends.cpp:19:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
                    ^
friends.cpp:20:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%s", s);
                   ^

• Subtask 1: 0 / 35
• Subtask 2: 0 / 65