TTRAVEL - Time Travel
Tác giả: RR
Ngôn ngữ: C++
#include <iostream>
#define FOR(i,a,b) for(long i=a; i<=b; i++)
#define MAXN 100111
using namespace std;
long father[MAXN],value[MAXN],n;
int main() {
// freopen("input.txt","r",stdin);
// freopen("output.txt","w",stdout);
scanf("%ld\n",&n);
long now=0; value[0]=-1;
FOR(i,1,n) {
char c; long u;
scanf("%c",&c);
if (c=='a') {
scanf("%ld\n",&u);
printf("%ld\n",u);
value[i]=u;
father[i]=now; now=i;
}
if (c=='s') {
scanf("\n");
father[i]=now;
now=father[now];
printf("%ld\n",value[now]);
}
if (c=='t') {
scanf("%ld\n",&u);
father[i]=now;
now=father[u];
printf("%ld\n",value[now]);
}
}
return 0;
}