Top 15 Easy DSA Google interview questions
Here, we will explore 15 basic DSA interview questions that are asked by Google in their interviews.
As promised in the previous blog, we are back with the top 15 DSA interview questions for Google. Just be ready to explore those 15 exciting questions.
But firstly we will start with easy questions to motivate you so you can also clear the Google interview. As we always hear getting placed in Google is just so hard. YES, it is true. But with your dedication and hard work, you can make it possible.
Now, we are getting started with the most common DSA Interview questions asked in Google interviews.
1. Add linked list:
Given two numbers represented by linked lists. Your task is to find the sum list and return the head of the sum list.
The sum list is a linked list representation of the addition of two numbers.
2. Roman to Integer
Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M.
Symbol Value
I 1
V 5
X 10
L 50
C 100
D 500
M 1000For example, 2 is written as II in Roman numeral, just two ones added together. 12 is written as, which is simply X + II. The number 27 is written as XXVII, which is XX + V + II.
Roman numerals are usually written from largest to smallest from left to right. However, the numeral for four is not IIII. Instead, the number four is written as IV. Because the one is before the five we subtract it making four. The same principle applies to the number nine, which is written as IX. There are six instances where subtraction is used:
Ican be placed beforeV(5) andX(10) to make 4 and 9.Xcan be placed beforeL(50) andC(100) to make 40 and 90.Ccan be placed beforeD(500) andM(1000) to make 400 and 900.
Given a Roman numeral, convert it to an integer.
3. Valid Parentheses
Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.
An input string is valid if:
- Open brackets must be closed by the same type of brackets.
- Open brackets must be closed in the correct order.
- Every close bracket has a corresponding open bracket of the same type.
4. Check If Linked List Is Palindrome
You are given a Singly Linked List of integers. You have to return true if the linked list is palindrome, else return false.
A Linked List is a palindrome if it reads the same from left to right and from right to left.
5. Plus One
You are given a large integer represented as an integer array digits, where each digits[i] is the ith digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading 0's.
Increment the large integer by one and return the resulting array of digits.
6. Painter’s Partition Problem
Given an array/list of length ’n’, where the array/list represents the boards and each element of the given array/list represents the length of each board. Some ‘k’ numbers of painters are available to paint these boards. Consider that each unit of a board takes 1 unit of time to paint.
You are supposed to return the area of the minimum time to get this job done of painting all the ’n’ boards under the constraint that any painter will only paint the continuous sections of boards.
Example :
Input: arr = [2, 1, 5, 6, 2, 3], k = 2Output: 117. Longest Common Prefix
Write a function to find the longest common prefix string amongst an array of strings.
If there is no common prefix, return an empty string "".
8. Climbing Stairs
You are climbing a staircase. It takes n steps to reach the top.
Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?
Example:
Input: n = 2
Output: 2
Explanation: There are two ways to climb to the top.
1. 1 step + 1 step
2. 2 steps9. Binary Tree Inorder Traversal
Given the root of a binary tree, return the inorder traversal of its nodes' values.
10. Pascal’s Triangle II
Given an integer rowIndex, return the rowIndexth (0-indexed) row of the Pascal's triangle.
In Pascal’s triangle, each number is the sum of the two numbers directly above it as shown:
11. Palindrome Number
Given an integer x, return true if x is a palindrome, and false otherwise.
12. Remove Element
Given an integer array nums and an integer val, remove all occurrences of val in nums in-place. The order of the elements may be changed. Then return the number of elements in nums which are not equal to val.
Consider the number of elements in nums which are not equal to val be k, to get accepted, you need to do the following things:
- Change the array
numssuch that the firstkelements ofnumscontain the elements which are not equal toval. The remaining elements ofnumsare not important as well as the size ofnums. - Return
k.
13. Remove Duplicates from Sorted Array
Given an integer array nums sorted in non-decreasing order, remove the duplicates in-place such that each unique element appears only once. The relative order of the elements should be kept the same. Then return the number of unique elements in nums.
Consider the number of unique elements of nums to be k, to get accepted, you need to do the following things:
- Change the array
numssuch that the firstkelements ofnumscontain the unique elements in the order they were present innumsinitially. The remaining elements ofnumsare not important as well as the size ofnums. - Return
k.
14. Symmetric Tree
Given the root of a binary tree, check whether it is a mirror of itself (i.e., symmetric around its center).
15. Length of Last Word
Given a string s consisting of words and spaces, return the length of the last word in the string.
A word is a maximal substring consisting of non-space characters only.
So, these are all easy 15 DSA Google Interview questions. Just try these out! Do practice. Then, in the next blog, we will discuss medium-level DSA problems for Google Interview.
All the best!
