Submission #151952

#	Time	Username	Problem	Language	Result	Execution time	Memory
151952		karma	Crayfish scrivener (IOI12_scrivener)	C++14	5 / 100	282 ms	69220 KiB

scrivener

#include <bits/stdc++.h>
#define ll      long long
#define pb      emplace_back
#define mp      make_pair
#define fi      first
#define se      second

using namespace std;

const int N = int(1e6) + 1;
const int logN = 21;

int cur, p[N][logN], ver[N], len[N];
char c[N];

void Init() {cur = 0;}

void TypeLetter(char ch) {
     ver[cur] = cur, c[cur] = ch;
     p[cur][0] = cur? cur - 1: cur;
     len[cur] = len[p[cur][0]] + 1;
     for(int i = 1; i < logN; ++i) p[cur][i] = p[p[cur][i - 1]][i - 1];
     ++cur;
}

void UndoCommands(int k) {
     ver[cur] = ver[cur - k - 1];
     len[cur] = len[ver[cur]];
     c[cur] = c[ver[cur]];
     ++cur;
}

char GetLetter(int k) {
     int  pos = ver[cur - 1];
     k = len[pos] - k - 1;
     for(int i = logN - 1; i >= 0; --i)
        if((k >> i) & 1) pos = p[pos][i];
     return c[pos];
}

//int main()
//{
//    ios_base::sync_with_stdio(0);
//    cin.tie(0), cout.tie(0);
//    if(fopen("test.inp", "r")) {
//        freopen("test.inp", "r", stdin);
//        freopen("test.out", "w", stdout);
//    }
//    Init();
//    TypeLetter('a');// a
//    TypeLetter('b');// ab
//    cout << GetLetter(1) << '\n';// b ab
//    TypeLetter('d');// abd
//    UndoCommands(2);// a
//    UndoCommands(1);// abd
//    cout << GetLetter(2) << '\n';// d abd
//    TypeLetter('e');// abde
//    UndoCommands(1);// abd
//    UndoCommands(5);// ab
//    TypeLetter('c');// abc
//    cout << GetLetter(2) << '\n';// c abc
//    UndoCommands(2);// abd
//    cout << GetLetter(2) << '\n';// d abd
//}

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