Submission #654296

#	Time	Username	Problem	Language	Result	Execution time	Memory
654296		as111	Crayfish scrivener (IOI12_scrivener)	C++17	5 / 100	409 ms	64164 KiB

scrivener

#include <iostream>

#define MAX 1000000

using namespace std;
char letter[MAX + 1];
int A[MAX + 1][21];
int back[MAX + 1]; // if undo, how far back to go, otherwise go back to current
int curr;
void Init() {
	for (int i = 0; i <= MAX; i++) {
		back[i] = i;
	}
	curr = 0;
}
void TypeLetter(char L) {
	curr++;
	letter[curr] = L;
	int prev = back[curr - 1]; // previous index
	A[curr][0] = prev;
	for (int j = 1; j <= 20; j++) {
		A[curr][j] = A[A[curr][j - 1]][j - 1];
	}
}
void UndoCommands(int U) {
	curr++;
	letter[curr] = '0';
	back[curr] = back[curr - U - 1]; // position to go back to
}
char GetLetter(int P) {
	P++;
	int pos = curr;
	for (int j = 20; j >= 0; j--) {
		if (A[pos][j] >= P) {
			pos = A[pos][j];
		}
	}
	return letter[pos];
}

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