oj.uz

Submission #340465

# Submission time Handle Problem Language Result Execution time Memory
340465 2020-12-27T16:18:45 Z blue Palindromic Partitions (CEOI17_palindromic) C++11
100 / 100
 487 ms 27828 KB 
#include <iostream>
#include <string>
using namespace std;

//a^p-1 = 1 mod p
//a^p-2 = 1/a mod p

long long p[1000001];
long long mod = 1e9 + 7;

long long prefhash[1000001];

long long pow(long long base, long long exp)
{
    if(exp == 0) return 1;
    if(exp % 2) return (pow(base, exp-1) * base) % mod;
    long long temp = pow(base, exp/2);
    return (temp * temp) % mod;
}

long long gethash(long long a, long long b)
{
    return (mod + prefhash[b] - (prefhash[a-1]*p[b-(a-1)]) % mod) % mod;
}

void run()
{
    string S;
    cin >> S;
    long long n = S.length();
    S = " " + S;

    // cout << S.substr(4, 4) << '\n';

    prefhash[0] = 0;
    for(long long i = 1; i <= n; i++) prefhash[i] = (p[1] * prefhash[i-1]  +  (S[i] - 'a' + 1)) % mod;

    long long res = 0;
    long long j = 1;
    for(long long i = 1; 1; i++)
    {
         // cout << "i = " << i << '\n';
         // cout << j << ' ' << i << ' ' << n-i+1 << ' ' << n-j+1 << '\n';
         // cout << S.substr(j, i-j+1) << ' ' << S.substr(n-i+1, (n-j+1) - (n-i+1) + 1) << '\n';
         // cout << gethash(j, i) << ' ' << gethash(n-i+1, n-j+1) << '\n';
        if(gethash(j, i) == gethash(n-i+1, n-j+1))
        {
            // cout << "temp2 " << j << ' ' << i << ' ' << n-i+1 << ' ' << n-j+1 << '\n';
            if(i == n-j+1)
            {
                res += 1;
                break;
            }
            else
            {
                res += 2;

                if(2*i == n) break;
            }
            j = i+1;
        }
        // cout << j << '\n';
        // cout << "temp " << i << ' ' << j << '\n';
    }
    cout << res << '\n';
}

int main()
{
    p[0] = 1;
    for(long long i = 1; i <= 1000000; i++) p[i] = (p[i-1] * 347) % mod;

    long long t;
    cin >> t;
    for(long long i = 1; i <= t; i++) run();
}

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 8172 KB Output is correct
2 Correct 11 ms 8172 KB Output is correct
3 Correct 11 ms 8172 KB Output is correct
4 Correct 11 ms 8172 KB Output is correct
5 Correct 11 ms 8172 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 8172 KB Output is correct
2 Correct 11 ms 8172 KB Output is correct
3 Correct 11 ms 8172 KB Output is correct
4 Correct 11 ms 8172 KB Output is correct
5 Correct 11 ms 8172 KB Output is correct
6 Correct 11 ms 8172 KB Output is correct
7 Correct 11 ms 8172 KB Output is correct
8 Correct 11 ms 8172 KB Output is correct
9 Correct 11 ms 8172 KB Output is correct

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 8172 KB Output is correct
2 Correct 11 ms 8172 KB Output is correct
3 Correct 11 ms 8172 KB Output is correct
4 Correct 11 ms 8172 KB Output is correct
5 Correct 11 ms 8172 KB Output is correct
6 Correct 11 ms 8172 KB Output is correct
7 Correct 11 ms 8172 KB Output is correct
8 Correct 11 ms 8172 KB Output is correct
9 Correct 11 ms 8172 KB Output is correct
10 Correct 15 ms 8300 KB Output is correct
11 Correct 14 ms 8300 KB Output is correct
12 Correct 15 ms 8300 KB Output is correct
13 Correct 15 ms 8300 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 8172 KB Output is correct
2 Correct 11 ms 8172 KB Output is correct
3 Correct 11 ms 8172 KB Output is correct
4 Correct 11 ms 8172 KB Output is correct
5 Correct 11 ms 8172 KB Output is correct
6 Correct 11 ms 8172 KB Output is correct
7 Correct 11 ms 8172 KB Output is correct
8 Correct 11 ms 8172 KB Output is correct
9 Correct 11 ms 8172 KB Output is correct
10 Correct 15 ms 8300 KB Output is correct
11 Correct 14 ms 8300 KB Output is correct
12 Correct 15 ms 8300 KB Output is correct
13 Correct 15 ms 8300 KB Output is correct
14 Correct 487 ms 27828 KB Output is correct
15 Correct 265 ms 22952 KB Output is correct
16 Correct 467 ms 27128 KB Output is correct
17 Correct 252 ms 18920 KB Output is correct