oj.uz

Submission #85912

# Submission time Handle Problem Language Result Execution time Memory
85912 2018-11-22T17:08:20 Z igzi Three Friends (BOI14_friends) C++17
100 / 100
 214 ms 35332 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;
}

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 22 ms 8188 KB Output is correct
2 Correct 22 ms 8188 KB Output is correct
3 Correct 24 ms 8248 KB Output is correct
4 Correct 21 ms 8324 KB Output is correct
5 Correct 22 ms 8340 KB Output is correct
6 Correct 21 ms 8516 KB Output is correct
7 Correct 21 ms 8516 KB Output is correct
8 Correct 21 ms 8528 KB Output is correct
9 Correct 22 ms 8528 KB Output is correct
10 Correct 21 ms 8528 KB Output is correct
11 Correct 21 ms 8528 KB Output is correct
12 Correct 21 ms 8528 KB Output is correct
13 Correct 22 ms 8528 KB Output is correct
14 Correct 21 ms 8528 KB Output is correct
15 Correct 22 ms 8528 KB Output is correct
16 Correct 21 ms 8528 KB Output is correct
17 Correct 22 ms 8528 KB Output is correct
18 Correct 21 ms 8528 KB Output is correct
19 Correct 22 ms 8528 KB Output is correct
20 Correct 22 ms 8528 KB Output is correct
21 Correct 22 ms 8528 KB Output is correct
22 Correct 35 ms 8528 KB Output is correct
23 Correct 22 ms 8528 KB Output is correct
24 Correct 2 ms 8528 KB Output is correct
25 Correct 2 ms 8528 KB Output is correct
26 Correct 2 ms 8528 KB Output is correct
27 Correct 2 ms 8528 KB Output is correct
28 Correct 2 ms 8528 KB Output is correct
29 Correct 2 ms 8528 KB Output is correct
30 Correct 2 ms 8528 KB Output is correct
31 Correct 2 ms 8528 KB Output is correct
32 Correct 2 ms 8528 KB Output is correct
33 Correct 2 ms 8528 KB Output is correct
34 Correct 2 ms 8528 KB Output is correct
35 Correct 2 ms 8528 KB Output is correct
36 Correct 2 ms 8528 KB Output is correct
37 Correct 2 ms 8528 KB Output is correct
38 Correct 2 ms 8528 KB Output is correct
39 Correct 2 ms 8528 KB Output is correct
40 Correct 2 ms 8528 KB Output is correct
41 Correct 2 ms 8528 KB Output is correct
42 Correct 2 ms 8528 KB Output is correct
43 Correct 21 ms 8528 KB Output is correct
44 Correct 22 ms 8528 KB Output is correct
45 Correct 22 ms 8528 KB Output is correct
46 Correct 39 ms 8528 KB Output is correct
47 Correct 22 ms 8528 KB Output is correct
48 Correct 23 ms 8528 KB Output is correct
49 Correct 2 ms 8528 KB Output is correct
50 Correct 22 ms 8528 KB Output is correct
51 Correct 23 ms 8528 KB Output is correct
52 Correct 24 ms 8528 KB Output is correct
53 Correct 24 ms 8528 KB Output is correct
54 Correct 21 ms 8528 KB Output is correct

Subtask #2
65.0 / 65.0

# Verdict Execution time Memory Grader output
1 Correct 118 ms 19196 KB Output is correct
2 Correct 146 ms 21132 KB Output is correct
3 Correct 115 ms 23216 KB Output is correct
4 Correct 129 ms 25256 KB Output is correct
5 Correct 113 ms 27112 KB Output is correct
6 Correct 16 ms 27112 KB Output is correct
7 Correct 214 ms 31072 KB Output is correct
8 Correct 76 ms 31072 KB Output is correct
9 Correct 120 ms 33448 KB Output is correct
10 Correct 127 ms 35192 KB Output is correct
11 Correct 78 ms 35332 KB Output is correct
12 Correct 21 ms 35332 KB Output is correct
13 Correct 22 ms 35332 KB Output is correct
14 Correct 21 ms 35332 KB Output is correct
15 Correct 21 ms 35332 KB Output is correct
16 Correct 22 ms 35332 KB Output is correct
17 Correct 23 ms 35332 KB Output is correct
18 Correct 23 ms 35332 KB Output is correct
19 Correct 21 ms 35332 KB Output is correct
20 Correct 21 ms 35332 KB Output is correct
21 Correct 21 ms 35332 KB Output is correct
22 Correct 21 ms 35332 KB Output is correct
23 Correct 21 ms 35332 KB Output is correct
24 Correct 21 ms 35332 KB Output is correct
25 Correct 21 ms 35332 KB Output is correct
26 Correct 21 ms 35332 KB Output is correct
27 Correct 22 ms 35332 KB Output is correct
28 Correct 21 ms 35332 KB Output is correct
29 Correct 21 ms 35332 KB Output is correct
30 Correct 21 ms 35332 KB Output is correct
31 Correct 21 ms 35332 KB Output is correct
32 Correct 22 ms 35332 KB Output is correct
33 Correct 22 ms 35332 KB Output is correct
34 Correct 21 ms 35332 KB Output is correct
35 Correct 2 ms 35332 KB Output is correct
36 Correct 2 ms 35332 KB Output is correct
37 Correct 3 ms 35332 KB Output is correct
38 Correct 3 ms 35332 KB Output is correct
39 Correct 2 ms 35332 KB Output is correct
40 Correct 3 ms 35332 KB Output is correct
41 Correct 2 ms 35332 KB Output is correct
42 Correct 2 ms 35332 KB Output is correct
43 Correct 23 ms 35332 KB Output is correct
44 Correct 2 ms 35332 KB Output is correct
45 Correct 2 ms 35332 KB Output is correct
46 Correct 3 ms 35332 KB Output is correct
47 Correct 2 ms 35332 KB Output is correct
48 Correct 2 ms 35332 KB Output is correct
49 Correct 2 ms 35332 KB Output is correct
50 Correct 2 ms 35332 KB Output is correct
51 Correct 2 ms 35332 KB Output is correct
52 Correct 2 ms 35332 KB Output is correct
53 Correct 2 ms 35332 KB Output is correct
54 Correct 22 ms 35332 KB Output is correct