Submission #574325

#	Time	Username	Problem	Language	Result	Execution time	Memory
574325		keta_tsimakuridze	Crayfish scrivener (IOI12_scrivener)	C++14	100 / 100	681 ms	107352 KiB

scrivener

#include<bits/stdc++.h>
#define prev Prev
using namespace std;
const int N = 1000005;
int id, c[N][25], prev[N], len[N];
vector<char> s;
void Init() {
	s.push_back('0');
}
void TypeLetter(char L) {
	id++;
	c[id][0] = id;
	s.push_back(L);
	len[id] = len[id - 1] + 1;
	prev[id] = c[id - 1][0];
	for(int i = 1;  i < 20; i++) {
		c[id][i] = c[prev[c[id][i - 1]]][i - 1];
	}
}
void UndoCommands(int U) {
	++id; s.push_back('0');
	int x = id - U - 1;
	len[id] = len[x];
	for(int i = 0; i < 20; i++) c[id][i] = c[x][i]; 
}
char GetLetter(int P) {
	int x = c[id][0];
	P = len[id] - P;
	for(int i = 20 - 1; i >= 0; i--) {
		if((1 << i) < P) x = prev[c[x][i]], P -= 1 << i; 
	}
	return s[c[x][0]];
}

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