Submission #314023

#	Time	Username	Problem	Language	Result	Execution time	Memory
314023		joseacaz	Crayfish scrivener (IOI12_scrivener)	C++17	100 / 100	787 ms	166776 KiB

scrivener

#include <bits/stdc++.h>
#define pb push_back
#define all(x) x.begin(), x.end()

using namespace std;
using ll = long long;
using vi = vector<int>;
using vl = vector<ll>;

const int LOG = 25;

struct Node
{
    Node* p[LOG];
    int len;
    char l;
};

const int MAXN = 1e6 + 5;
int curr = 0;
Node* last[MAXN];

void Init()
{
    last[0] = nullptr;
    curr = 1;
}

void TypeLetter(char L)
{
    last[curr] = new Node();
    last[curr] -> l = L;
    last[curr] -> len = (last[curr - 1] ? last[curr - 1] -> len : 0) + 1;
    last[curr] -> p[0] = last[curr - 1];
    

    for(int i = 1; i < LOG; i++)
        last[curr] -> p[i] = nullptr;
    for(int i = 1; i < LOG; i++)
        if(last[curr] -> p[i - 1] != nullptr)
            last[curr] -> p[i] = (last[curr] -> p[i - 1]) -> p[i - 1];

    curr++;
}

void UndoCommands(int U)
{
    last[curr] = last[curr - U - 1];
    curr++;
}

char GetLetter(int P)
{
    Node* aux = last[curr - 1];
    P = (aux -> len) - P - 1;
    
    for(int i = LOG - 1; i >= 0; i--)
        if(P & (1 << i))
            aux = (aux -> p[i]);
    return (aux -> l);
            
}

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