Answer Posted / hex

to be more generic this kind of problem is best solved
recursivly.

To point out that 2 ^ N AND 3 ^ N are both wrong,
here's a few examples: (the exponet is the amount of levels)
2^0 = 1, correct
2^1 = 2, incorrect, should be 3
2^2 = 4, incorrect, should be 7

And a tree with three children
3^0 = 1, correct
3^1 = 3, incorrect, should be 4
3^2 = 9, incorrect, should be 13

Looking at that I'm sure you can see the pattern.
Let
C = "Number of Possible Children"
N = Levels

N
Σ C^N
j=0

or in C++ code
int NodeCount(int C, int N)
{
if (N < 0) return 0
return NodeCount(C, N-1) + C^N
}

What do you mean by garbage collection?

962

---

Why do we use hashset?

937

---

How does arraylist size work?

901

---

Is hashmap sorted?

955

---

What happens if we put duplicate key in hashmap?

869

---

What is the time complexity of selection sort?

870

---

What is data and data structure?

960

---

What is difference between array and arraylist? When will you use array over arraylist?

988

---

What does arrays tostring do?

884

---

Does map extend iterable?

947

---

How does a selection sort work for an array?

931

---

Does hashmap preserve insertion order?

890

---

How do you find the height of a binary tree?

899

---

How do you find the depth of a binary tree?

981

---

Mention for which header list, you will found the last node contains the null pointer?

853

---