oj.uz

Submission #619063

# Submission time Handle Problem Language Result Execution time Memory
619063 2022-08-02T09:37:42 Z jophyyjh Palindromic Partitions (CEOI17_palindromic) C++14
60 / 100
 1121 ms 1648 KB 
/**
 * Notes during contest.
 * 
 * ------ A ------
 * In the example, (3,7,6,6) is the set of optimal pillars to select. Well, I assume
 * that the subset of pillars shall be connected in order?
 * 
 * ------ B ------
 * [S1-2] is solvable with a O(n^2) dp (Z-array + dp). I also have a hunch that we
 * can pass [S3] too (#time_limit = 10s). Oh no... I really suck at str processing
 * problems...
 * 
 * ------ C ------
 * 
 * Time Complexity 1: O()
 * Time Complexity 2: O(n^2)
 * Time Complexity 3: O()
 * Implementation 1
*/
 
#include <bits/stdc++.h>
 
typedef int64_t     int_t;
typedef std::vector<int_t>  vec;
 
 
inline vec z_array(const std::string& s) {
    int_t n = s.size();
    vec z(n, 0);
    for (int_t k = 1, x = 0, y = 1; k < n; k++) {
        z[k] = std::max(std::min(z[k - x], y - k + 1), int_t(0));
        while (k + z[k] < n && s[k + z[k]] == s[z[k]])
            x = k, y = k + z[k], z[k]++;
    }
    // std::cerr << "[debug] " << s << std::endl;
    // for (int_t a : z)
    //     std::cerr << a << ' ';
    // std::cerr << std::endl;
    return z;
}
 
int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(NULL);
 
    int_t T;
    std::cin >> T;
    for (int_t tc = 1; tc <= T; tc++) {
        std::string str;
        std::cin >> str;
        int_t n = str.length();
        if (n > 10000) {
            std::cout << "bye\n";
            return 0;
        }
        
        
        vec dp(n, 1);
        for (int_t k = (n - 1) / 2; k >= 0; k--) {
            std::string substr = str.substr(k, n - 2 * k);
            vec Z = z_array(substr);
            for (int_t i = n - 2 * k - 1; i > 0; i--) {
                assert(Z[i] <= n - 2 * k - i);
                if (Z[i] != n - 2 * k - i || 2 * Z[i] > n - 2 * k)
                    continue;
                if (2 * Z[i] == n - 2 * k) {    // even palindrome
                    dp[k] = std::max(dp[k], int_t(2));
                } else {    // odd palindrome
                    dp[k] = std::max(dp[k], dp[k + Z[i]] + 2);
                }
            }
        }
        std::cout << dp[0] << '\n';
    }
}

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 320 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 324 KB Output is correct
5 Correct 0 ms 316 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 320 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 324 KB Output is correct
5 Correct 0 ms 316 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 2 ms 316 KB Output is correct

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 320 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 324 KB Output is correct
5 Correct 0 ms 316 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 2 ms 316 KB Output is correct
10 Correct 1121 ms 684 KB Output is correct
11 Correct 519 ms 652 KB Output is correct
12 Correct 741 ms 748 KB Output is correct
13 Correct 568 ms 624 KB Output is correct

Subtask #4
0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 320 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 324 KB Output is correct
5 Correct 0 ms 316 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 2 ms 316 KB Output is correct
10 Correct 1121 ms 684 KB Output is correct
11 Correct 519 ms 652 KB Output is correct
12 Correct 741 ms 748 KB Output is correct
13 Correct 568 ms 624 KB Output is correct
14 Incorrect 3 ms 1648 KB Output isn't correct
15 Halted 0 ms 0 KB -