Groupon Software Engineer Interview Questions and Answers

Find the missing smallest positive integer in an array of integers

• Sort the array to easily identify missing integers

• Iterate through the sorted array to find the smallest missing positive integer

• Return the missing integer

Sort an array of strings containing only 0, 1, and 2.

• Use a three-way partitioning algorithm like Dutch National Flag algorithm to sort the array in a single pass.

• Keep track of three pointers - low, mid, and high to partition the array into three sections.

• Swap elements based on their values to achieve the sorted array.

Leaves of a tree are the nodes with no children in a tree data structure.

• Traverse the tree and identify nodes with no children.

• Use depth-first search or breadth-first search algorithms to find leaves.

• Examples: In a binary tree, leaves are nodes with no left or right child.

• In a general tree, leaves are nodes with no children in their child list.

The Lowest Common Ancestor (LCA) of a tree is the shared ancestor of two nodes farthest from the root.

• Start from the root and traverse the tree to find the paths from the root to the two nodes.

• Compare the paths to find the last common node between them, which is the LCA.

• If one of the nodes is an ancestor of the other, then the ancestor node is the LCA.

I have worked on projects involving web development, mobile app development, and data analysis.

• Developed a web application using React and Node.js for a client in the e-commerce industry

• Created a mobile app using Flutter for a startup in the healthcare sector

• Performed data analysis on customer behavior using Python and SQL for a marketing company

I completed internships at ABC Company and XYZ Company during my undergraduate studies.

• Interned at ABC Company working on web development projects

• Interned at XYZ Company assisting with software testing and quality assurance

• Gained hands-on experience in coding, debugging, and problem-solving