Submission #13500

#	Time	Username	Problem	Language	Result	Execution time	Memory
13500		tncks0121	Crayfish scrivener (IOI12_scrivener)	C++14	100 / 100	622 ms	130460 KiB

scrivener

#include<stdio.h>
  
const int MAXC = 1000005;
const int lgMAXC = 20;
  
struct node{
    char letter;
    int level;
    node* parent[lgMAXC];
  
    node(char letter, node* par): letter(letter){
        parent[0] = par;
        if(par != NULL) level = par->level + 1; else level = 0;
        for(int i=1; i<lgMAXC; i++){
            if(parent[i-1] == NULL) parent[i] = NULL;
            else parent[i] = parent[i-1]->parent[i-1];
        }
    }
};
  
node* Commands[MAXC];
node* now;
int N;
  
void Init(){
    now = new node(0, NULL);
    Commands[1] = now; N = 1;
}
  
void TypeLetter(char L){
    Commands[++N] = new node(L, now);
    now = Commands[N];
}
  
void UndoCommands(int U){
    int val = N - U; Commands[++N] = Commands[val];
    now = Commands[N];
}
  
char GetLetter(int P){ ++P;
    node* tmp = now; int L = now->level - P;
    for(int i=0; (1<<i)<=L; i++) if(L & (1<<i)){
        tmp = tmp->parent[i];
    }
    return tmp->letter;
}

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