Submission #1005367

#	Time	Username	Problem	Language	Result	Execution time	Memory
1005367		pawned	Crayfish scrivener (IOI12_scrivener)	C++17	26 / 100	101 ms	37204 KiB

scrivener

#pragma GCC optimize("O1,O2,O3,Ofast,unroll-loops")

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define pb push_back
typedef long long ll;
typedef pair<int, int> ii;
typedef vector<int> vi;

const int MAX = 1e6 + 5;

int moves = 1;
vi cuts;	// position to start adding letters

vi rt(MAX);	// prev time if reverting
vector<pair<int, char>> ch(MAX);	// (pos, character added) at time
vi len(MAX);	// length at time

string curr;

void Init() {
	for (int i = 0; i < MAX; i++) {
		rt[i] = i;
	}
	ch[0] = {-1, '!'};
}

void print() {
	cout<<"cuts: ";
	for (int x : cuts)
		cout<<x<<" ";
	cout<<endl;
	cout<<"curr: "<<curr<<endl;
}

void TypeLetter(char L) {
	ch[moves] = {len[moves - 1], L};
	len[moves] = len[moves - 1] + 1;
	moves++;
}

void UndoCommands(int U) {
	rt[moves] = moves - U - 1;
	len[moves] = len[moves - U - 1];
	moves++;
}

string ans;

void precomp() {	// find the whole string
/*	cout<<"rt: ";
	for (int i = 0; i < 15; i++) {
		cout<<rt[i]<<" ";
	}
	cout<<endl;
	cout<<"ch: ";
	for (int i = 0; i < 15; i++) {
		cout<<i<<": {"<<ch[i].fi<<", "<<ch[i].se<<"}; ";
	}
	cout<<endl;*/
	int curr = moves - 1;
	while (curr > 0) {
		while (rt[curr] < curr)
			curr = rt[curr];
//		cout<<"at "<<curr<<endl;
		ans += ch[curr].se;
		curr--;
	}
	reverse(ans.begin(), ans.end());
//	cout<<"ans: "<<ans<<endl;
}

int ctr = 0;

char GetLetter(int P) {
	if (ctr == 0)
		precomp();
	ctr++;
	return ans[P];
}

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