# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
914377 | VMaksimoski008 | Crayfish scrivener (IOI12_scrivener) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
int up[1000001][LOG], id=0, len[1000001];
char s[1000001];
void Init() { s[0] = ' '; }
void TypeLetter(char ch) {
s[++id] = ch;
len[id] = len[id-1] + 1;
up[id][0] = id - 1;
for(int i=1; i<21; i++) up[id][i] = up[ up[id][i-1] ][i-1];
}
void UndoCommands(int u) {
int prev = (++id) - u - 1;
s[id] = s[prev];
len[id] = len[prev];
up[id][0] = up[prev][0];
for(int i=1; i<21; i++) up[id][i] = up[ up[id][i-1] ][i-1];
}
char GetLetter(int p) {
int L = len[id]-p-1, pos = id;
for(int i=20; i>=0; i--)
if(L & (1 << i)) pos = up[pos][i];
return s[pos];
}