# The Accountant - Google Top Interview Questions

### Problem Statement :

```Spreadsheets often use this alphabetical encoding for its columns: "A", "B", "C", ..., "AA", "AB", "AC", ..., "ZZ", "AAA", "AAB", "AAC", ....

Given a column number n, return its alphabetical column id. For example, given 1, return "A". Given 27, return "AA".

Constraints

1 ≤ n < 2 ** 31

Example 1

Input

n = 1

Output

"A"

Example 2

Input

n = 2
Output

"B"

Example 3

Input

n = 26

Output

"Z"

Example 4

Input

n = 27

Output

"AA"```

### Solution :

```                        ```Solution in C++ :

string solve(int n) {
string result;
while (n > 0) {
// Since in code 'A' + 25 = 'Z'
n--;

// Get the remainder to identify
// the current character to be
// added to the column number
int curr = n % 26;

// Divide by 26 to process the
// next character
n = n / 26;

// Update the result with the
// current character
result.push_back(curr + 'A');
}

// Since we are adding the most
// significant character to the end
// of the string, reverse it before
// returning
reverse(result.begin(), result.end());

return result;
}```
```

```                        ```Solution in Java :

import java.util.*;

class Solution {
public String solve(int A) {
String s = "";
int counter = 0;
while (A > 0) {
counter = (A - 1) % 26;
char a = (char) ('A' + counter);
s = a + s;
A = (A - 1) / 26;
}
return s;
}
}```
```

```                        ```Solution in Python :

class Solution:
def solve(self, n):

ans = ""

# because we have 1 based indexing
# we need to scale 1-27 to 0-26 each time
# so, we use n-1
while n >= 1:
ans += chr((n - 1) % 26 + ord("A"))
n = (n - 1) // 26

return ans[::-1]```
```

## Tree: Height of a Binary Tree

The height of a binary tree is the number of edges between the tree's root and its furthest leaf. For example, the following binary tree is of height : image Function Description Complete the getHeight or height function in the editor. It must return the height of a binary tree as an integer. getHeight or height has the following parameter(s): root: a reference to the root of a binary

## Tree : Top View

Given a pointer to the root of a binary tree, print the top view of the binary tree. The tree as seen from the top the nodes, is called the top view of the tree. For example : 1 \ 2 \ 5 / \ 3 6 \ 4 Top View : 1 -> 2 -> 5 -> 6 Complete the function topView and print the resulting values on a single line separated by space.

## Tree: Level Order Traversal

Given a pointer to the root of a binary tree, you need to print the level order traversal of this tree. In level-order traversal, nodes are visited level by level from left to right. Complete the function levelOrder and print the values in a single line separated by a space. For example: 1 \ 2 \ 5 / \ 3 6 \ 4 F

## Binary Search Tree : Insertion

You are given a pointer to the root of a binary search tree and values to be inserted into the tree. Insert the values into their appropriate position in the binary search tree and return the root of the updated binary tree. You just have to complete the function. Input Format You are given a function, Node * insert (Node * root ,int data) { } Constraints No. of nodes in the tree <

## Tree: Huffman Decoding

Huffman coding assigns variable length codewords to fixed length input characters based on their frequencies. More frequent characters are assigned shorter codewords and less frequent characters are assigned longer codewords. All edges along the path to a character contain a code digit. If they are on the left side of the tree, they will be a 0 (zero). If on the right, they'll be a 1 (one). Only t

## Binary Search Tree : Lowest Common Ancestor

You are given pointer to the root of the binary search tree and two values v1 and v2. You need to return the lowest common ancestor (LCA) of v1 and v2 in the binary search tree. In the diagram above, the lowest common ancestor of the nodes 4 and 6 is the node 3. Node 3 is the lowest node which has nodes and as descendants. Function Description Complete the function lca in the editor b