#include <iostream>
using namespace std;
int main()
{
unsigned int n, x[99], y[99], i, j=0;
cin>>n;
for (i=1;i<=n;i++)
cin>>x[i];
for (i=1;i<=n;i++)
if (x[i]>=100 && x[i]<=999)
{
j++;
y[j]=x[i];
}
for (i=1;i<=j;i++)
cout<<y[i]<<" ";
return 0;
}
Sper că te-am ajutat :)