Submission #641518

#	Time	Username	Problem	Language	Result	Execution time	Memory
641518		ymm	Crayfish scrivener (IOI12_scrivener)	C++17	34 / 100	1078 ms	244936 KiB

scrivener

#include <bits/stdc++.h>
#define Loop(x,l,r) for (ll x = (l); x < (r); ++x)
#define LoopR(x,l,r) for (ll x = (r)-1; x >= (l); --x)
typedef long long ll;
typedef std::pair<int, int> pii;
typedef std::pair<ll , ll > pll;
using namespace std;

const int lg = 16;

struct node {
	node *par_com[lg];
	node *par_let[lg];
	int len;
	char let;
} *cur;

node pool[250'000'000/sizeof(node)];
int next_node = 0;

node *new_node()
{
	return pool + (next_node++);
}
	

void Init()
{
	cur = new_node();
	Loop (i,0,lg) {
		cur->par_com[i] = cur;
		cur->par_let[i] = cur;
	}
	cur->len = 0;
	cur->let = 0;
}

void TypeLetter(char L)
{
	node *next = new_node();
	next->par_com[0] = cur;
	next->par_let[0] = cur;
	Loop (i,0,lg-1) {
		next->par_com[i+1] = next->par_com[i]->par_com[i];
		next->par_let[i+1] = next->par_let[i]->par_let[i];
	}
	next->len = next->par_let[0]->len + 1;
	next->let = L;
	cur = next;
}

void UndoCommands(int U)
{
	node *sib = cur;
	while (U >= (1 << lg)) {
		sib = sib->par_com[lg-1];
		U -= 1 << (lg-1);
	}
	Loop (i,0,lg) {
		if (U & (1<<i))
			sib = sib->par_com[i];
	}
	node *next = new_node();
	next->par_com[0] = cur;
	next->par_let[0] = sib->par_let[0];
	Loop (i,0,lg-1) {
		next->par_com[i+1] = next->par_com[i]->par_com[i];
		next->par_let[i+1] = next->par_let[i]->par_let[i];
	}
	next->len = next->par_let[0]->len + 1;
	next->let = sib->let;
	cur = next;
}

char GetLetter(int P)
{
	P = cur->len - 1 - P;
	node *ans = cur;
	while (P >= (1 << lg)) {
		ans = ans->par_let[lg-1];
		P -= 1 << (lg-1);
	}
	Loop (i,0,lg) {
		if (P & (1<<i))
			ans = ans->par_let[i];
	}
	return ans->let;
}

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