Submission #98738

#	Time	Username	Problem	Language	Result	Execution time	Memory
98738		Alexa2001	Crayfish scrivener (IOI12_scrivener)	C++17	60 / 100	1054 ms	94504 KiB

scrivener

#include <bits/stdc++.h>

using namespace std;

const int Nmax = 1e6 + 5, lg = 20;

int nodes, t[lg+2][Nmax], up[Nmax], frst_up[Nmax];
char letter[Nmax];

void Init()
{
}

void TypeLetter(char L)
{
    letter[++nodes] = L;
    t[0][nodes] = frst_up[nodes - 1];
    up[nodes] = up[nodes - 1] + 1;
    frst_up[nodes] = nodes;

    int i;
    for(i=1; i<=lg; ++i)
        t[i][nodes] = t[i-1][t[i-1][nodes]];
}

void UndoCommands(int U)
{
    int cursor = nodes - U, i;

    t[0][nodes + 1] = cursor;
    up[++nodes] = up[cursor];
    frst_up[nodes] = frst_up[cursor];
}

char GetLetter(int P)
{
    int i, x = frst_up[nodes]; ++P;
    for(i=lg; i>=0; --i)
        if(up[t[i][x]] >= P) x = t[i][x];
    return letter[x];
}

Compilation message (stderr)

scrivener.cpp: In function 'void UndoCommands(int)':
scrivener.cpp:28:29: warning: unused variable 'i' [-Wunused-variable]
     int cursor = nodes - U, i;
                             ^

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