oj.uz

Submission #77255

# Submission time Handle Problem Language Result Execution time Memory
77255 2018-09-24T12:48:41 Z FutymyClone Three Friends (BOI14_friends) C++14
100 / 100
 211 ms 19612 KB 
#include <bits/stdc++.h>

using namespace std;

const int N = 2e6 + 5;
const int base = 317;
const int mod = 1e9 + 2277;

int n, Hash[N], Pow[N], cnt[26];
char s[N];
set <int> st;

void prepare(){
    Pow[0] = 1;
    for (int i = 1; i < N; i++) Pow[i] = (1LL * Pow[i - 1] * base) % mod;
    for (int i = 1; i <= n; i++) Hash[i] = (1LL * Hash[i - 1] * base + s[i]) % mod;
}

int get (int l, int r) {
    if (l > r) return 0;
    return ((1LL * Hash[r] - 1LL * Hash[l - 1] * Pow[r - l + 1] % mod) % mod + mod) % mod;
}

int main(){
    scanf("%d", &n);
    scanf("%s", s + 1);
    for (int i = 1; i <= n; i++) cnt[s[i] - 'A']++;
    int odd = 0;
    for (int i = 0; i < 26; i++) if (cnt[i] & 1) odd++;

    if (odd != 1 || n % 2 == 0) return !printf("NOT POSSIBLE");
    prepare();

    int res = 0;
    int pos = -1;

    for (int i = 1; i <= n; i++) {
        if (cnt[s[i] - 'A'] % 2 == 0) continue;
        if (i < (n + 1) / 2) {
            int cur = get(1, i - 1);
            int nxt = get(i + 1, (n + 1) / 2);
            int cur2 = get((n + 1) / 2 + 1, (n + 1) / 2 + 1 + i - 2);
            int nxt2 = get((n + 1) / 2 + 1 + i - 1, n);

            if (cur == cur2 && nxt == nxt2) {
                res++;
                st.insert(get((n + 1) / 2 + 1, n));
                if (res == 1) pos = i;
            }
        }
        else if (i == (n + 1) / 2) {
            int cur = get(1, i - 1);
            int nxt = get(i + 1, n);
            if (cur == nxt) {
                res++;
                st.insert(get(1, i - 1));
                if (res == 1) pos = i;
            }
        }
        else {
            int cur = get((n + 1) / 2, i - 1);
            int nxt = get(i + 1, n);
            int cur2 = get(1, i - (n + 1) / 2);
            int nxt2 = get(i - (n + 1) / 2 + 1, (n + 1) / 2 - 1);
            if (cur == cur2 && nxt == nxt2) {
                res++;
                st.insert(get(1, (n + 1) / 2 - 1));
                if (res == 1) pos = i;
            }
        }
    }

    if (pos == -1) return !printf("NOT POSSIBLE");
    if (st.size() > 1) printf("NOT UNIQUE");
    else {
        int dem = 0, ptr = 1;
        while (dem < n / 2) {
            if (ptr == pos) {
                ptr++;
                continue;
            }
            dem++;
            printf("%c", s[ptr++]);
        }
    }
    return 0;
}
/*
5
AAABA
*/

Compilation message

friends.cpp: In function 'int main()':
friends.cpp:25:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
friends.cpp:26:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%s", s + 1);
     ~~~~~^~~~~~~~~~~~~

Subtask #1
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 8184 KB Output is correct
2 Correct 21 ms 8244 KB Output is correct
3 Correct 21 ms 8256 KB Output is correct
4 Correct 21 ms 8276 KB Output is correct
5 Correct 21 ms 8280 KB Output is correct
6 Correct 21 ms 8324 KB Output is correct
7 Correct 21 ms 8356 KB Output is correct
8 Correct 21 ms 8376 KB Output is correct
9 Correct 21 ms 8380 KB Output is correct
10 Correct 22 ms 8384 KB Output is correct
11 Correct 21 ms 8392 KB Output is correct
12 Correct 21 ms 8452 KB Output is correct
13 Correct 22 ms 8456 KB Output is correct
14 Correct 22 ms 8456 KB Output is correct
15 Correct 21 ms 8484 KB Output is correct
16 Correct 21 ms 8492 KB Output is correct
17 Correct 21 ms 8492 KB Output is correct
18 Correct 21 ms 8492 KB Output is correct
19 Correct 21 ms 8496 KB Output is correct
20 Correct 21 ms 8500 KB Output is correct
21 Correct 21 ms 8500 KB Output is correct
22 Correct 21 ms 8508 KB Output is correct
23 Correct 21 ms 8516 KB Output is correct
24 Correct 2 ms 8516 KB Output is correct
25 Correct 2 ms 8516 KB Output is correct
26 Correct 2 ms 8516 KB Output is correct
27 Correct 2 ms 8516 KB Output is correct
28 Correct 2 ms 8516 KB Output is correct
29 Correct 2 ms 8516 KB Output is correct
30 Correct 2 ms 8516 KB Output is correct
31 Correct 2 ms 8516 KB Output is correct
32 Correct 2 ms 8516 KB Output is correct
33 Correct 2 ms 8516 KB Output is correct
34 Correct 2 ms 8516 KB Output is correct
35 Correct 3 ms 8516 KB Output is correct
36 Correct 2 ms 8516 KB Output is correct
37 Correct 2 ms 8516 KB Output is correct
38 Correct 2 ms 8516 KB Output is correct
39 Correct 2 ms 8516 KB Output is correct
40 Correct 2 ms 8516 KB Output is correct
41 Correct 2 ms 8516 KB Output is correct
42 Correct 2 ms 8516 KB Output is correct
43 Correct 23 ms 8692 KB Output is correct
44 Correct 23 ms 8692 KB Output is correct
45 Correct 23 ms 8700 KB Output is correct
46 Correct 23 ms 8700 KB Output is correct
47 Correct 21 ms 8712 KB Output is correct
48 Correct 21 ms 8712 KB Output is correct
49 Correct 2 ms 8712 KB Output is correct
50 Correct 21 ms 8720 KB Output is correct
51 Correct 21 ms 8724 KB Output is correct
52 Correct 21 ms 8728 KB Output is correct
53 Correct 21 ms 8732 KB Output is correct
54 Correct 21 ms 8732 KB Output is correct

Subtask #2
65.0 / 65.0

# Verdict Execution time Memory Grader output
1 Correct 127 ms 19492 KB Output is correct
2 Correct 112 ms 19508 KB Output is correct
3 Correct 111 ms 19612 KB Output is correct
4 Correct 124 ms 19612 KB Output is correct
5 Correct 112 ms 19612 KB Output is correct
6 Correct 15 ms 19612 KB Output is correct
7 Correct 211 ms 19612 KB Output is correct
8 Correct 75 ms 19612 KB Output is correct
9 Correct 121 ms 19612 KB Output is correct
10 Correct 154 ms 19612 KB Output is correct
11 Correct 74 ms 19612 KB Output is correct
12 Correct 21 ms 19612 KB Output is correct
13 Correct 21 ms 19612 KB Output is correct
14 Correct 21 ms 19612 KB Output is correct
15 Correct 21 ms 19612 KB Output is correct
16 Correct 21 ms 19612 KB Output is correct
17 Correct 21 ms 19612 KB Output is correct
18 Correct 21 ms 19612 KB Output is correct
19 Correct 21 ms 19612 KB Output is correct
20 Correct 21 ms 19612 KB Output is correct
21 Correct 21 ms 19612 KB Output is correct
22 Correct 21 ms 19612 KB Output is correct
23 Correct 21 ms 19612 KB Output is correct
24 Correct 21 ms 19612 KB Output is correct
25 Correct 21 ms 19612 KB Output is correct
26 Correct 21 ms 19612 KB Output is correct
27 Correct 21 ms 19612 KB Output is correct
28 Correct 21 ms 19612 KB Output is correct
29 Correct 21 ms 19612 KB Output is correct
30 Correct 21 ms 19612 KB Output is correct
31 Correct 21 ms 19612 KB Output is correct
32 Correct 21 ms 19612 KB Output is correct
33 Correct 22 ms 19612 KB Output is correct
34 Correct 21 ms 19612 KB Output is correct
35 Correct 2 ms 19612 KB Output is correct
36 Correct 2 ms 19612 KB Output is correct
37 Correct 2 ms 19612 KB Output is correct
38 Correct 2 ms 19612 KB Output is correct
39 Correct 3 ms 19612 KB Output is correct
40 Correct 2 ms 19612 KB Output is correct
41 Correct 3 ms 19612 KB Output is correct
42 Correct 2 ms 19612 KB Output is correct
43 Correct 21 ms 19612 KB Output is correct
44 Correct 2 ms 19612 KB Output is correct
45 Correct 2 ms 19612 KB Output is correct
46 Correct 2 ms 19612 KB Output is correct
47 Correct 2 ms 19612 KB Output is correct
48 Correct 2 ms 19612 KB Output is correct
49 Correct 2 ms 19612 KB Output is correct
50 Correct 2 ms 19612 KB Output is correct
51 Correct 2 ms 19612 KB Output is correct
52 Correct 2 ms 19612 KB Output is correct
53 Correct 2 ms 19612 KB Output is correct
54 Correct 21 ms 19612 KB Output is correct