C++ :
void staircase(int n) {
int num = n;
for(int i = 1; i <= n; i++){
for(int j = (n - i); j > 0; j--){
cout << " ";
}
for(int k = 0; k < i; k++){
cout << "#";
}
cout << endl;
}
}
Explanation:
This is one of our favorites. Used to print stars (*) in school assignments previously, now we are printing hashtags (#). The loop for j is to take care of the spaces, the loop for k is to take care of the #. The i loop is to take care of printing the correct newline. Yes, this solution is not pretty with this many for loops. The timing for this is O² still, since there are 2 layers of nested loops.