Submission #60698

#	Time	Username	Problem	Language	Result	Execution time	Memory
60698		aome	Crayfish scrivener (IOI12_scrivener)	C++17	100 / 100	784 ms	144416 KiB

scrivener

#include <bits/stdc++.h>

using namespace std;

const int N = 1000005;

int cur;
int cnt1, cnt2;
int h[N];
int par[20][N];
int arr[N];
char a[N];

void Init() {}

void TypeLetter(char L) {
	++cnt1;
	par[0][cnt1] = cur, h[cnt1] = h[cur] + 1;
	cur = cnt1, a[cur] = L;
	for (int i = 1; i < 20; ++i) {
		par[i][cur] = par[i - 1][par[i - 1][cur]];
	}
	arr[++cnt2] = cur;
}

void UndoCommands(int U) {
	cur = arr[cnt2 + 1] = arr[cnt2 - U];
	++cnt2;
}

char GetLetter(int P) {
	int pos = cur;
	int H = h[cur] - (P + 1);
	for (int i = 19; i >= 0; --i) {
		if (H >= (1 << i)) {
			H -= (1 << i), pos = par[i][pos];
		}
	}
	return a[pos];
}

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