oj.uz

답안 #821830

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
821830 2023-08-11T18:15:16 Z serifefedartar 세 명의 친구들 (BOI14_friends) C++17
100 / 100
 70 ms 34724 KB 
#include <bits/stdc++.h>
using namespace std;
 
#define fast ios::sync_with_stdio(0);cin.tie(0);
typedef long long ll;
#define f first
#define s second
#define MOD 1000000009
#define LOGN 20
#define MAXN 2000100
 
const ll A = 9973;
ll powA[MAXN];
ll hashes[MAXN];
ll hash_ss(int l, int r) {
    ll ans = (hashes[r] - (hashes[l-1] * powA[r-l + 1] % MOD)) % MOD;
    while (ans < 0)
        ans += MOD;
    return ans;
}
 
ll hash_concat(int l1, int r1, int l2, int r2) {
    ll ans = (hash_ss(l2, r2) + (hash_ss(l1, r1) * powA[r2 - l2 + 1] % MOD)) % MOD;
    return ans;
}
 
int cnt[26];
int main() {
    fast
    powA[0] = 1;
    for (int i = 1; i < MAXN; i++)
        powA[i] = (powA[i-1] * A) % MOD;
 
    int N;
    string S;
    cin >> N >> S;
    S = "#" + S;
 
    if (N % 2 == 0) {
        cout << "NOT POSSIBLE\n";
        return 0;
    }
 
    hashes[0] = 0;
    for (int i = 1; i <= N; i++)
        hashes[i] = (hashes[i-1] * A + (S[i] - 'A' + 1)) % MOD;

    int len = N / 2;
    bool left = 0, right = 0;
    ll leftmostH = hash_ss(1, len);
    ll rightmostH = hash_ss(N-len+1, N);
    if (leftmostH == rightmostH) {
        for (int i = 1; i <= len; i++)
            cout << S[i];
        cout << "\n";
        return 0;
    }

    ll left_hash, right_hash; 
    for (int i = 1; i <= N/2; i++) {
        if (i == 1)
            left_hash = hash_ss(2, N/2+1);
        else
            left_hash = hash_concat(1, i - 1, i + 1, N/2+1);

        if (left_hash == rightmostH)
            right = true;
    }

    for (int i = N/2+1; i <= N; i++) {
        if (i == N)
            right_hash = hash_ss(N/2+1, N-1);
        else
            right_hash = hash_concat(N/2+1, i - 1, i + 1, N); 

        if (right_hash == leftmostH)
            left = true;
    }

    if (!left && !right)
        cout << "NOT POSSIBLE\n";
    else if (left && !right) {
        for (int i = 1; i <= len; i++)
            cout << S[i];
        cout << "\n";
    } else if (right && !left) {
        for (int i = N-len+1; i <= N; i++)
            cout << S[i];
        cout << "\n";
    } else if (left && right)
        cout << "NOT UNIQUE\n";
}

Subtask #1
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 14 ms 15956 KB Output is correct
2 Correct 13 ms 15952 KB Output is correct
3 Correct 14 ms 15964 KB Output is correct
4 Correct 13 ms 15860 KB Output is correct
5 Correct 13 ms 15956 KB Output is correct
6 Correct 14 ms 15884 KB Output is correct
7 Correct 14 ms 15956 KB Output is correct
8 Correct 15 ms 15880 KB Output is correct
9 Correct 14 ms 15956 KB Output is correct
10 Correct 14 ms 15980 KB Output is correct
11 Correct 13 ms 15920 KB Output is correct
12 Correct 13 ms 15932 KB Output is correct
13 Correct 14 ms 15916 KB Output is correct
14 Correct 13 ms 15880 KB Output is correct
15 Correct 14 ms 15980 KB Output is correct
16 Correct 14 ms 15956 KB Output is correct
17 Correct 17 ms 15956 KB Output is correct
18 Correct 14 ms 15916 KB Output is correct
19 Correct 14 ms 15956 KB Output is correct
20 Correct 14 ms 15976 KB Output is correct
21 Correct 13 ms 15976 KB Output is correct
22 Correct 15 ms 15972 KB Output is correct
23 Correct 16 ms 16084 KB Output is correct
24 Correct 13 ms 15912 KB Output is correct
25 Correct 13 ms 15956 KB Output is correct
26 Correct 14 ms 15908 KB Output is correct
27 Correct 14 ms 15884 KB Output is correct
28 Correct 14 ms 15956 KB Output is correct
29 Correct 14 ms 15932 KB Output is correct
30 Correct 14 ms 15956 KB Output is correct
31 Correct 14 ms 15948 KB Output is correct
32 Correct 14 ms 15896 KB Output is correct
33 Correct 14 ms 15956 KB Output is correct
34 Correct 14 ms 15956 KB Output is correct
35 Correct 13 ms 15904 KB Output is correct
36 Correct 16 ms 15956 KB Output is correct
37 Correct 14 ms 15864 KB Output is correct
38 Correct 15 ms 15892 KB Output is correct
39 Correct 16 ms 15956 KB Output is correct
40 Correct 15 ms 16028 KB Output is correct
41 Correct 14 ms 15944 KB Output is correct
42 Correct 14 ms 15920 KB Output is correct
43 Correct 14 ms 15956 KB Output is correct
44 Correct 14 ms 15956 KB Output is correct
45 Correct 14 ms 15956 KB Output is correct
46 Correct 14 ms 15932 KB Output is correct
47 Correct 14 ms 15984 KB Output is correct
48 Correct 14 ms 15956 KB Output is correct
49 Correct 15 ms 15856 KB Output is correct
50 Correct 14 ms 15956 KB Output is correct
51 Correct 13 ms 15896 KB Output is correct
52 Correct 14 ms 15912 KB Output is correct
53 Correct 14 ms 15928 KB Output is correct
54 Correct 14 ms 15956 KB Output is correct

Subtask #2
65.0 / 65.0

# 결과 실행 시간 메모리 Grader output
1 Correct 70 ms 34612 KB Output is correct
2 Correct 66 ms 34616 KB Output is correct
3 Correct 64 ms 34668 KB Output is correct
4 Correct 66 ms 34604 KB Output is correct
5 Correct 68 ms 34708 KB Output is correct
6 Correct 17 ms 19940 KB Output is correct
7 Correct 48 ms 34724 KB Output is correct
8 Correct 45 ms 31880 KB Output is correct
9 Correct 61 ms 34548 KB Output is correct
10 Correct 60 ms 34612 KB Output is correct
11 Correct 44 ms 32364 KB Output is correct
12 Correct 14 ms 15956 KB Output is correct
13 Correct 14 ms 15988 KB Output is correct
14 Correct 14 ms 15936 KB Output is correct
15 Correct 14 ms 15972 KB Output is correct
16 Correct 14 ms 15864 KB Output is correct
17 Correct 16 ms 15952 KB Output is correct
18 Correct 14 ms 15944 KB Output is correct
19 Correct 15 ms 15876 KB Output is correct
20 Correct 14 ms 15988 KB Output is correct
21 Correct 14 ms 15968 KB Output is correct
22 Correct 14 ms 15988 KB Output is correct
23 Correct 14 ms 15984 KB Output is correct
24 Correct 14 ms 15988 KB Output is correct
25 Correct 14 ms 15956 KB Output is correct
26 Correct 14 ms 15988 KB Output is correct
27 Correct 14 ms 16116 KB Output is correct
28 Correct 15 ms 15988 KB Output is correct
29 Correct 14 ms 15984 KB Output is correct
30 Correct 14 ms 15992 KB Output is correct
31 Correct 14 ms 15984 KB Output is correct
32 Correct 14 ms 15956 KB Output is correct
33 Correct 14 ms 15920 KB Output is correct
34 Correct 14 ms 15956 KB Output is correct
35 Correct 14 ms 15988 KB Output is correct
36 Correct 14 ms 15900 KB Output is correct
37 Correct 14 ms 15880 KB Output is correct
38 Correct 14 ms 15968 KB Output is correct
39 Correct 14 ms 15956 KB Output is correct
40 Correct 15 ms 15904 KB Output is correct
41 Correct 14 ms 15908 KB Output is correct
42 Correct 14 ms 15956 KB Output is correct
43 Correct 14 ms 15988 KB Output is correct
44 Correct 14 ms 15952 KB Output is correct
45 Correct 14 ms 15916 KB Output is correct
46 Correct 14 ms 15984 KB Output is correct
47 Correct 14 ms 15980 KB Output is correct
48 Correct 14 ms 15980 KB Output is correct
49 Correct 14 ms 15956 KB Output is correct
50 Correct 15 ms 15948 KB Output is correct
51 Correct 15 ms 15956 KB Output is correct
52 Correct 15 ms 15944 KB Output is correct
53 Correct 14 ms 15972 KB Output is correct
54 Correct 13 ms 15900 KB Output is correct