Submission #1036269

#	Time	Username	Problem	Language	Result	Execution time	Memory
1036269		stdfloat	Crayfish scrivener (IOI12_scrivener)	C++17	100 / 100	479 ms	133940 KiB

scrivener

#include <bits/stdc++.h>
using namespace std;

const int N = (int)1e6 + 1;

int q, cnt, cur;

vector<char> ch(N);

vector<int> num(N), d(N);

vector<vector<int>> sp(N, vector<int>(20));

void Init() {}

void TypeLetter(char L) {
    num[++q] = ++cnt;

    ch[cnt] = L;
    d[cnt] = d[cur] + 1;

    sp[cnt][0] = cur;
    for (int i = 1; i < 20; i++) sp[cnt][i] = sp[sp[cnt][i - 1]][i - 1];

    cur = cnt;
}

void UndoCommands(int U) {
    q++;

    num[q] = cur = num[q - U - 1];
}

char GetLetter(int P) {
    int x = cur;
    for (int i = 19; i >= 0; i--) {
        if (P < d[x] - (1 << i)) x = sp[x][i];
    }

    return ch[x];
}

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