INTERVIEW

# 10 Important Paytm Coding Interview Questions

By Archana

If you are in a rush to crack that Paytm coding Interview Questions round then here is a short pocketbook that you should go through. Make sure you practice all the 10 coding questions in here, (and study the related ones) because these are the most asked Paytm coding interview questions, say the interviewees!

1. Top 10 Paytm Coding Interview Questions
• Given an integer number, convert it to a roman numeral.
• Given a string s, reverse the order of words.
• Sort an array of 0s, 1s and 2s
• Convert a Binary Tree into its Mirror Tree
• Remove duplicates from an unsorted linked list
• Write a function to get the Nth node in a Linked List
• Delete a node in a Doubly Linked List
• Delete all the nodes from the doubly linked list that are greater than a given value
• Interchange elements of the first and last rows in the matrix
• Write a function to print the ZigZag order traversal of a binary tree.
2. More Paytm coding interview questions

## Top 10 Paytm Coding Interview Questions

Coding comes in handy when you practise it several times. And one coding question can solve multiple related queries on the go. So do practise as many coding questions as you can!

Before diving into the next section, ensure you’re solid on full-stack development essentials like front-end frameworks, back-end technologies, and database management. If you are looking for a detailed Full Stack Development career program, you can join GUVI’s Full Stack Development Career Program with placement assistance. You will be able to master the MERN stack (MongoDB, Express.js, React, Node.js) and build real-life projects.

Additionally, if you would like to explore JavaScript through a self-paced course, try GUVI’s JavaScript self-paced certification course.

### 1. Given an integer number, convert it to a roman numeral.

Answer: A combination of some symbols represent Roman numerals.

Sample Input:

num: 10

Expected output:

“X”

#### Code: IntegerToRoman.java

public class IntegerToRoman

{

//method to convert integer to roman

//function that converts an integer to roman

public static String intToRoman(int number)

{

//creating an array of place values

String[] thousands = {“”, “M”, “MM”, “MMM”};

String[] hundreds = {“”, “C”, “CC”, “CCC”, “CD”, “D”, “DC”, “DCC”, “DCCC”, “CM”};

String[] tens = {“”, “X”, “XX”, “XXX”, “XL”, “L”, “LX”, “LXX”, “LXXX”, “XC”};

String[] units = {“”, “I”, “II”, “III”, “IV”, “V”, “VI”, “VII”, “VIII”, “IX”};

return thousands[number / 1000] + hundreds[(number % 1000) / 100] + tens[(number % 100) / 10] + units[number % 10];

}

public static void main(String args[])

{

//creating an array of integers to be converted into roman

int[] numbers = {13, 21, 38, 50, 190, 141, 117, 120, 125, 138, 149, 6, 712, 181, 197, 918, 199, 1100, 1101, 1248, 1253};

for (int number: numbers)

{

System.out.printf(“%4d -> %8s\n”, number, intToRoman(number));

}

}

}

Output:

### 2. Given a string s, reverse the order of words.

Sample Input

``````life is beautiful
enjoy it
live upto it``````

Expected Output

``````beautiful is life
it enjoy
it upto live``````

#### Code:

``````class Solution {
String reverseWords(String s) {
int numOfWords = 1;
for (int i = 0; i < s.length(); i++) {
if(s.charAt(i) == ' ') {
numOfWords++;
}
}
String[] allWords = new  String[numOfWords];
String currentWord = "";
int index = 0;
for(int i = 0; i < s.length(); i++) {
if(s.charAt(i) == ' ') {
allWords[index++] = currentWord;
currentWord = "";
} else {
currentWord += s.charAt(i);
}
}
allWords[index++] = currentWord;
String ans = "";
for(int i = index - 1; i > 0; i--) {
ans += allWords[i];
ans += ' ';
}
ans += allWords[0];
return ans;
}
}``````

### 3. Sort an array of 0s, 1s and 2s

Sample Input:

{0, 1, 2, 0, 1, 2}

Output:

{0, 0, 1, 1, 2, 2}

#### Code:

`import java.io.*;`

`classcountzot{`

`    ``// Sort the input array, the array is assumed to`

`    ``// have values in {0, 1, 2}`

`    static void sort 012(inta[], intarr_size){`

`        ``int``lo = ``0``;`

`        ``int``hi = arr_size - ``1``;`

`        ``int``mid = ``0``, temp = ``0``;`

`        // Iterate till all the elements` `are sorted`

`        ``while``(mid <= hi) {`

`            ``switch``(a[mid]) {`

`                ``// If the element is 0`

`            ``case``0``: {`

`                ``temp = a[lo];`

`                ``a[lo] = a[mid];`

`                ``a[mid] = temp;`

`                ``lo++;`

`                ``mid++;`

`                ``break``;`

`            ``}`

`                ``// If the element is 1`

`            ``case``1``:`

`                ``mid++;`

`                ``break``;`

`                ``// If the element is 2`

`            ``case``2``: {`

`                ``temp = a[mid];`

`                ``a[mid] = a[hi];`

`                ``a[hi] = temp;`

`                ``hi--;`

`                ``break``;`

`            ``}`

`            ``}`

`        ``}`

`    ``}`

`    ``/* Utility function to print array arr[] */`

`    static void print Array(intarr[], intarr_size){`

`        ``int``i;`

`        ``for``(i = ``0``; i < arr_size; i++)`

`            ``System.out.print(arr[i] + ``" "``);`

`        ``System.out.println(``""``);`

`    ``}`

`    ``/*Driver function to check for above functions*/`

`    public static void main(String[] args){`

`        ``int``arr[] = { ``0``, ``1``, ``1``, ``0``, ``1``, ``2``, ``1``, ``2``, ``0``, ``0``, ``0``, ``1``};`

`        ``int``arr_size = arr.length;`

`        sort012(arr, arr_size);`

`        ``printArray(arr, arr_size);`

`    ``}`

`}`

Practise more Paytm coding interview questions: Placement Preparation with GUVI

### 4. Convert a Binary Tree into its Mirror Tree

#### Code:

Output

```Binary tree is

4 2 5 1 3

Mirror tree is

3 1 5 2 4 ```

### 5. Remove duplicates from an unsorted linked list

Input:

Output:

12->11->21->41->43.

Code:

Output

```Linked list before removing duplicates 10 12 11 11 12 11 10
Linked list after removing duplicates 10 12 11 ```

More articles related to Paytm coding interview questions: Interview Questions

### 6. Write a function to get the Nth node in a Linked List

```Input:  5->10->15->20,  index = 2
Output: 15
The node at index 2 is 15```

Output

`Element at index 3 is 4`

### 7. Delete a node in a Doubly Linked List

#### Code:

Output

```Original Linked list 12  9  6  3

### 8. Delete all the nodes from the doubly linked list that are greater than a given value

Input: 20 31 6 3 11, X = 11
Output: 6 3 11

#### Code:

Output

```Original List: 10 8 4 11 9
Modified List: 8 4 9 ```

### 9. Interchange elements of the first and last rows in the matrix

One of the most asked Paytm coding interview questions:

Input: 6 4 7 0 5
3 2 7 1 2
4 8 1 2 6
5 6 1 1 2

Output: 5 6 1 1 2
3 2 7 1 2
4 8 1 2 6
6 4 7 0 5

#### Code:

Output

```9 9 7 7
4 7 6 5
3 2 1 8
8 9 7 6 ```

### 10. Write a function to print the ZigZag order traversal of a binary tree.

The zigzag order traversal for the below binary tree will be 1 3 2 7 6 5 4.

#### Code:

Output

```ZigZag Order traversal of binary tree is
1 3 2 7 6 5 4 ```

## More Paytm coding interview questions

Definitely, there is more to this. Find the top Paytm coding interview questions on our award-winning practice platform- CODEKATA: where practice always makes you perfect!

For more Paytm coding interview-related questions click here: Placement Preparation with GUVI

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