Submission #1004119

#	Time	Username	Problem	Language	Result	Execution time	Memory
1004119		Ausp3x	Crayfish scrivener (IOI12_scrivener)	C++17	5 / 100	1068 ms	8340 KiB

scrivener

// 人外有人，天外有天
// author: Ausp3x

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>

typedef long long             lng;
typedef unsigned int          uint;
typedef unsigned long long    ulng;
using namespace std;
using namespace __gnu_pbds;

int const INF32 = 0x3f3f3f3f;
lng const INF64 = 0x3f3f3f3f3f3f3f3f;

map<int, vector<int>> Trie;
vector<int> history(1, -1);

int getLen(int c) {
    int len = 0;
    while (c != -1) {
        len += 1 << Trie[c].size() - 1;
        c = Trie[c][Trie[c].size() - 1];
    }

    return len;
}

int queryUp(int c, int q) {
    int i = 0;
    while (q > 0) {
        if (i >= Trie[c].size())
            return -2;

        if (q & 1)
            c = Trie[c][i];
        
        i++;
        q >>= 1;
    }

    return c;
}

void Init() {
    Trie[-1];
    
    return;
}

void TypeLetter(char l) {
    int prv = history.back(), p_lv = (prv == -1 ? -1 : prv / 26);
    int cur = 26 * (p_lv + 1) + (l - 'a');
    if (Trie[cur].size() == 0) {
        Trie[cur].push_back(prv);
        for (int i = 1; i < 20; i++) {
            if (queryUp(prv, (1 << i) - 1) == -2)
                break;
                
            Trie[cur].push_back(queryUp(prv, (1 << i) - 1));
        }
    }

    history.push_back(cur);

    return;
}

void UndoCommands(int u) {
    history.push_back(history[history.size() - u - 1]);

    return;
}

char GetLetter(int p) {
    int len = getLen(history.back());

    return 'a' + (queryUp(history.back(), len - p - 1) % 26);
}

/*
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    Init();
    TypeLetter('a');
    TypeLetter('b');
    cout << GetLetter(1) << endl;
    TypeLetter('d');
    UndoCommands(2);
    UndoCommands(1);
    cout << GetLetter(2) << endl;
    TypeLetter('e');
    UndoCommands(1);
    UndoCommands(5);
    TypeLetter('c');
    cout << GetLetter(2) << endl;
    UndoCommands(2);
    cout << GetLetter(2) << endl;

    return 0;
}
//*/

Compilation message (stderr)

scrivener.cpp: In function 'int getLen(int)':
scrivener.cpp:22:36: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   22 |         len += 1 << Trie[c].size() - 1;
      |                     ~~~~~~~~~~~~~~~^~~
scrivener.cpp: In function 'int queryUp(int, int)':
scrivener.cpp:32:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |         if (i >= Trie[c].size())
      |             ~~^~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 0 / 7
• Subtask 3: 0 / 22
• Subtask 4: 0 / 26
• Subtask 5: 0 / 40