Submission #1229615

#	Time	Username	Problem	Language	Result	Execution time	Memory
1229615		msrivera1404	Hieroglyphs (IOI24_hieroglyphs)	C++20	3 / 100	251 ms	4168 KiB

hieroglyphs

#include "hieroglyphs.h"
#include<bits/stdc++.h>

bool is_subsequence(const std::vector<int>& s, const std::vector<int>& t) {
    if (s.empty()) {
        return true;
    }
    if (t.empty()) {
        return false; 
    }

    int s_ptr = 0;
    int t_ptr = 0;

    while (s_ptr < s.size() && t_ptr < t.size()) {
        if (s[s_ptr] == t[t_ptr]) {
            s_ptr++;
        }
        t_ptr++;
    }
    return s_ptr == s.size(); 
}
std::vector<int> get_common_prefix(const std::vector<int>& a, const std::vector<int>& b) {
    std::vector<int> common_prefix;
    int min_len = std::min(a.size(), b.size());
    for (int i = 0; i < min_len; ++i) {
        if (a[i] == b[i]) {
            common_prefix.push_back(a[i]);
        } else {
            break;
        }
    }
    return common_prefix;
}
std::vector<int> get_common_suffix(const std::vector<int>& a, const std::vector<int>& b) {
    std::vector<int> common_suffix;
    int i_a = a.size() - 1;
    int i_b = b.size() - 1;

    while (i_a >= 0 && i_b >= 0 && a[i_a] == b[i_b]) {
        common_suffix.insert(common_suffix.begin(), a[i_a]); 
        i_a--;
        i_b--;
    }
    return common_suffix;
}
std::pair<bool, int> is_monotone(const std::vector<int>& seq) {
    if (seq.empty()) {
        return {true, -1}; 
    }

    int first_val = seq[0];
    for (int x : seq) {
        if (x != first_val) {
            return {false, -1}; 
        }
    }
    return {true, first_val}; 
}


std::vector<int> ucs(std::vector<int> A, std::vector<int> B) {
    std::vector<int> ucs_prefix = get_common_prefix(A, B);

    std::vector<int> A_prime(A.begin() + ucs_prefix.size(), A.end());
    std::vector<int> B_prime(B.begin() + ucs_prefix.size(), B.end());

    std::vector<int> ucs_suffix = get_common_suffix(A_prime, B_prime);

    std::vector<int> A_middle(A_prime.begin(), A_prime.end() - ucs_suffix.size());
    std::vector<int> B_middle(B_prime.begin(), B_prime.end() - ucs_suffix.size());

    std::vector<int> ucs_middle;

    if (is_subsequence(A_middle, B_middle)) {
        ucs_middle = A_middle;
    } else if (is_subsequence(B_middle, A_middle)) {
        ucs_middle = B_middle;
    } else {
        std::pair<bool, int> mono_A = is_monotone(A_middle);
        std::pair<bool, int> mono_B = is_monotone(B_middle);

        if (A_middle.empty() || B_middle.empty()) {
            ucs_middle = {}; 
        } else if (mono_A.first && !mono_B.first) {
            ucs_middle = A_middle;
        } else if (mono_B.first && !mono_A.first) {
            ucs_middle = B_middle;
        } else if (mono_A.first && mono_B.first && mono_A.second != mono_B.second) {
            ucs_middle = {};
        } else {
            return {-1};
        }
    }

    std::vector<int> final_ucs;
    final_ucs.reserve(ucs_prefix.size() + ucs_middle.size() + ucs_suffix.size());
    final_ucs.insert(final_ucs.end(), ucs_prefix.begin(), ucs_prefix.end());
    final_ucs.insert(final_ucs.end(), ucs_middle.begin(), ucs_middle.end());
    final_ucs.insert(final_ucs.end(), ucs_suffix.begin(), ucs_suffix.end());

    return final_ucs;
}

• Subtask 0: 0 / 0
• Subtask 1: 3 / 3
• Subtask 2: 0 / 15
• Subtask 3: 0 / 10
• Subtask 4: 0 / 16
• Subtask 5: 0 / 14
• Subtask 6: 0 / 42