oj.uz

답안 #196872

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
196872 2020-01-17T11:15:24 Z jovan_b 세 명의 친구들 (BOI14_friends) C++17
100 / 100
 113 ms 22952 KB 
#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef long double ld;
 
int n, len;
 
const int MOD = 1000000007;
const int p = 31;
 
int hs[2000005];
 
int add(int a, int b){
    return (a+b)%MOD;
}
 
int mul(int a, int b){
    return (1LL*a*b)%MOD;
}
 
int pw(int a, int b){
    if(b == 0) return 1;
    int res = pw(a, b/2);
    res = mul(res, res);
    if(b%2) res = mul(res, a);
    return res;
}
 
int powers[2000005];
 
int substring_hash(int l, int r){
    if(l == 0) return hs[r];
    /*cout << hs[r] << endl;
    cout << hs[l-1] << endl;*/
    return add(hs[r], mul(powers[r-l+1], MOD - hs[l-1]));
}
 
int main(){
    ios_base::sync_with_stdio(false);
    cout.precision(10);
    cout<<fixed;
 
    cin >> n;
    if(n%2 == 0){
        cout << "NOT POSSIBLE\n";
        return 0;
    }
    powers[0] = 1;
    len = n/2;
    for(int i=1; i<=2000002; i++){
        powers[i] = mul(p, powers[i-1]);
    }
    string s;
    cin >> s;
    hs[0] = (s[0]-'A') + 1;
    for(int i=1; i<n; i++){
        hs[i] = add(mul(p, hs[i-1]), (s[i]-'A') + 1);
    }
    //cout << substring_hash(4, 6) << endl;
    //return 0;
    string res = "nema";
    int hashres = -500;
    int inv = pw(p, MOD-2);
    for(int i=0; i<len; i++){
        int a = 0;
        if(i) a = add(a, substring_hash(0, i-1));
        a = add(mul(a, powers[len-i]), substring_hash(i+1, len));
        int b = substring_hash(len+1, n-1);
        if(a == b){
            if(b == hashres) continue;
            if(res == "nema"){
                res = "";
                for(int j=len+1; j<n; j++) res += s[j];
                hashres = b;
            }
            else{
                cout << "NOT UNIQUE\n";
                return 0;
            }
        }
    }
    for(int i=len+1; i<n; i++){
        int a = substring_hash(0, len-1);
        int b = substring_hash(len, i-1);
        if(i != n-1) b = add(mul(b, powers[n-i-1]), substring_hash(i+1, n-1));
        if(a == b){
            if(a == hashres) continue;
            if(res == "nema"){
                res = "";
                for(int j=0; j<len; j++) res += s[j];
                hashres = a;
            }
            else{
                cout << "NOT UNIQUE\n";
                return 0;
            }
        }
    }
    int a = substring_hash(0, len-1);
    int b = substring_hash(len+1, n-1);
    //cout << a << " " << b << endl;
    if(a == b){
        if(a == hashres){
 
        }
        else if(res == "nema"){
            res = "";
            for(int j=0; j<len; j++) res += s[j];
            hashres = a;
        }
        else{
            cout << "NOT UNIQUE\n";
            return 0;
        }
    }
    if(res == "nema"){
        cout << "NOT POSSIBLE\n";
    }
    else cout << res << "\n";
    return 0;
}

Compilation message

friends.cpp: In function 'int main()':
friends.cpp:64:9: warning: unused variable 'inv' [-Wunused-variable]
     int inv = pw(p, MOD-2);
         ^~~

Subtask #1
35.0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 21 ms 8292 KB Output is correct
2 Correct 20 ms 8184 KB Output is correct
3 Correct 20 ms 8184 KB Output is correct
4 Correct 20 ms 8184 KB Output is correct
5 Correct 21 ms 8184 KB Output is correct
6 Correct 21 ms 8184 KB Output is correct
7 Correct 21 ms 8184 KB Output is correct
8 Correct 20 ms 8184 KB Output is correct
9 Correct 21 ms 8184 KB Output is correct
10 Correct 21 ms 8184 KB Output is correct
11 Correct 20 ms 8184 KB Output is correct
12 Correct 21 ms 8188 KB Output is correct
13 Correct 22 ms 8156 KB Output is correct
14 Correct 22 ms 8184 KB Output is correct
15 Correct 21 ms 8184 KB Output is correct
16 Correct 23 ms 8204 KB Output is correct
17 Correct 21 ms 8184 KB Output is correct
18 Correct 19 ms 8184 KB Output is correct
19 Correct 21 ms 8184 KB Output is correct
20 Correct 20 ms 8196 KB Output is correct
21 Correct 20 ms 8184 KB Output is correct
22 Correct 24 ms 8312 KB Output is correct
23 Correct 21 ms 8184 KB Output is correct
24 Correct 2 ms 376 KB Output is correct
25 Correct 2 ms 376 KB Output is correct
26 Correct 2 ms 376 KB Output is correct
27 Correct 21 ms 8184 KB Output is correct
28 Correct 21 ms 8184 KB Output is correct
29 Correct 21 ms 8184 KB Output is correct
30 Correct 21 ms 8184 KB Output is correct
31 Correct 21 ms 8156 KB Output is correct
32 Correct 21 ms 8184 KB Output is correct
33 Correct 20 ms 8184 KB Output is correct
34 Correct 21 ms 8188 KB Output is correct
35 Correct 21 ms 8184 KB Output is correct
36 Correct 21 ms 8184 KB Output is correct
37 Correct 20 ms 8184 KB Output is correct
38 Correct 21 ms 8184 KB Output is correct
39 Correct 21 ms 8184 KB Output is correct
40 Correct 20 ms 8172 KB Output is correct
41 Correct 20 ms 8184 KB Output is correct
42 Correct 20 ms 8184 KB Output is correct
43 Correct 21 ms 8184 KB Output is correct
44 Correct 20 ms 8184 KB Output is correct
45 Correct 21 ms 8184 KB Output is correct
46 Correct 21 ms 8192 KB Output is correct
47 Correct 21 ms 8184 KB Output is correct
48 Correct 21 ms 8184 KB Output is correct
49 Correct 2 ms 376 KB Output is correct
50 Correct 21 ms 8184 KB Output is correct
51 Correct 21 ms 8184 KB Output is correct
52 Correct 21 ms 8188 KB Output is correct
53 Correct 21 ms 8184 KB Output is correct
54 Correct 21 ms 8184 KB Output is correct

Subtask #2
65.0 / 65.0

# 결과 실행 시간 메모리 Grader output
1 Correct 108 ms 22952 KB Output is correct
2 Correct 108 ms 22816 KB Output is correct
3 Correct 107 ms 22796 KB Output is correct
4 Correct 107 ms 22812 KB Output is correct
5 Correct 111 ms 22888 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 113 ms 22808 KB Output is correct
8 Correct 104 ms 20764 KB Output is correct
9 Correct 104 ms 21504 KB Output is correct
10 Correct 101 ms 21516 KB Output is correct
11 Correct 89 ms 18076 KB Output is correct
12 Correct 23 ms 8184 KB Output is correct
13 Correct 21 ms 8184 KB Output is correct
14 Correct 20 ms 8184 KB Output is correct
15 Correct 20 ms 8184 KB Output is correct
16 Correct 20 ms 8156 KB Output is correct
17 Correct 21 ms 8184 KB Output is correct
18 Correct 21 ms 8184 KB Output is correct
19 Correct 21 ms 8184 KB Output is correct
20 Correct 21 ms 8184 KB Output is correct
21 Correct 21 ms 8184 KB Output is correct
22 Correct 21 ms 8184 KB Output is correct
23 Correct 21 ms 8156 KB Output is correct
24 Correct 21 ms 8156 KB Output is correct
25 Correct 20 ms 8184 KB Output is correct
26 Correct 21 ms 8188 KB Output is correct
27 Correct 21 ms 8184 KB Output is correct
28 Correct 22 ms 8184 KB Output is correct
29 Correct 21 ms 8156 KB Output is correct
30 Correct 21 ms 8184 KB Output is correct
31 Correct 20 ms 8184 KB Output is correct
32 Correct 30 ms 8188 KB Output is correct
33 Correct 20 ms 8188 KB Output is correct
34 Correct 21 ms 8184 KB Output is correct
35 Correct 2 ms 376 KB Output is correct
36 Correct 2 ms 376 KB Output is correct
37 Correct 2 ms 376 KB Output is correct
38 Correct 21 ms 8184 KB Output is correct
39 Correct 21 ms 8184 KB Output is correct
40 Correct 20 ms 8184 KB Output is correct
41 Correct 20 ms 8184 KB Output is correct
42 Correct 20 ms 8184 KB Output is correct
43 Correct 20 ms 8184 KB Output is correct
44 Correct 21 ms 8184 KB Output is correct
45 Correct 21 ms 8184 KB Output is correct
46 Correct 21 ms 8184 KB Output is correct
47 Correct 20 ms 8184 KB Output is correct
48 Correct 21 ms 8184 KB Output is correct
49 Correct 21 ms 8184 KB Output is correct
50 Correct 21 ms 8184 KB Output is correct
51 Correct 21 ms 8184 KB Output is correct
52 Correct 21 ms 8184 KB Output is correct
53 Correct 21 ms 8312 KB Output is correct
54 Correct 21 ms 8184 KB Output is correct