Submission #415918

#	Time	Username	Problem	Language	Result	Execution time	Memory
415918		arayi	Crayfish scrivener (IOI12_scrivener)	C++17	34 / 100	1098 ms	97324 KiB

scrivener

#include <vector>
#include <algorithm>
#include <set>
#define ad push_back
using namespace std;
const int N = 1e6 + 10;

int a[N], i1 = 1;
int p[N][20];
char c[N];
set<int> fp;
void Init() 
{
	fp.insert(0);
}

void TypeLetter(char L) 
{
	a[i1] = a[i1 - 1] + 1;
	c[i1] = L;
	i1++;
}

void UndoCommands(int U) 
{
	a[i1] = a[i1 - U - 1];
	fp.insert(i1);
	auto i = fp.lower_bound(i1 - U);
	p[i1][0] = *(--i);
	//printf("%d %d\n", i1, p[i1][0]);
	for (int i = 1; i < 20; i++) p[i1][i] = p[p[i1][i - 1]][i - 1];
	i1++;
}

char GetLetter(int P) 
{
	P++;
	auto s = *(--fp.end());
	//printf("%d\n", s);
	for (int i = 20 - 1; i >= 0; i--)
		if (a[p[s][i]] >= P)s = p[s][i];
	if(a[s] >= P) s = p[s][0];
	s += P - a[s];
	return c[s];
}

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