Submission #18853

#	Time	Username	Problem	Language	Result	Execution time	Memory
18853		suhgyuho_william	Crayfish scrivener (IOI12_scrivener)	C++98	100 / 100	462 ms	95804 KiB

scrivener

#include <stdio.h>

int rear,cnt;
int par[1000010][22];
int next[1000010];
int many[1000010];
char a[1000010];

void Init(){
	rear = cnt = 0;
}

void TypeLetter(char L) {
	int i;

	rear++; cnt++;
	next[cnt] = rear;
	a[rear] = L;
	par[rear][0] = next[cnt-1];
	for(i=1; i<=19; i++){
		par[rear][i] = par[par[rear][i-1]][i-1];
	}
	many[cnt] = many[cnt-1]+1;
}

void UndoCommands(int U) {
	cnt++;
	next[cnt] = next[cnt-U-1];
	many[cnt] = many[cnt-U-1];
}

char GetLetter(int P) {
	int i,x;
	int ans;

	ans = next[cnt];
	x = many[cnt]-(P+1);
	//printf("%d %d\n",ans,x);
	for(i=19; i>=0; i--){
		if(x >= (1 << i)){
			ans = par[ans][i];
			x -= (1 << i);
		}
	}
	return a[ans];
}

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