Submission #76872

#	Time	Username	Problem	Language	Result	Execution time	Memory
76872		FiloSanza	Crayfish scrivener (IOI12_scrivener)	C++14	100 / 100	853 ms	208136 KiB

scrivener

#include <bits/stdc++.h>

using namespace std;

const int MAX_LOG = 20;
const int MAX_SIZE = 26;
struct Node{
	char val;
	int depth;
	map<char, Node*> figli;
	Node* father[MAX_LOG];

	Node(char val, int depth) : val(val), depth(depth){
		for(int i=0; i<MAX_LOG; i++)
			father[i] = nullptr;
	}
	Node(char val, int depth, Node* N) : val(val), depth(depth){
		father[0] = N;
		for(int i=1; i<MAX_LOG; i++)
			if(father[i-1] != nullptr)
				father[i] = father[i-1]->father[i-1];
			else
				father[i] = nullptr;
	}
};

Node* root;
vector<Node*> version;

void Init() {
	root = new Node('\0', -1);
	version.push_back(root);
}

void TypeLetter(char L) {
	//aggiungi la lettera come nuova versione
	if(version.back()->figli.count(L-'a') == 0){
		version.back()->figli[L-'a'] = new Node(L, version.back()->depth+1, version.back());
	}
	version.push_back(version.back()->figli[L-'a']);
}

void UndoCommands(int U) {
	version.push_back(version[version.size()-U-1]);
}

char GetLetter(int P) {
	Node* node = version.back();
	int L = version.back()->depth - P;
	for(int i=0; (1<<i)<=L; i++)if(L&(1<<i))
		node = node->father[i];
	return node->val;
}

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