10+ C Developer Interview Questions and Answers for Freshers

Given a string and an integer, create a new string by selecting the smallest character from the first K characters of the input string and repeating the process until the input string is empty.

• Iterate through the input string, selecting the smallest character from the first K characters each time.

• Remove the selected character from the input string and append it to the new string.

• Continue this process until the input string is empty.

• Return the final new string formed.

Merge K sorted arrays into a single sorted array.

• Create a min heap to store the first element of each array along with the array index.

• Pop the top element from the heap, add it to the result array, and push the next element from the same array back to the heap.

• Continue this process until all elements are processed.

• Time complexity can be optimized using a priority queue or merge sort technique.

Sort an array of 0s, 1s, and 2s in linear time complexity.

• Use three pointers to keep track of 0s, 1s, and 2s while iterating through the array.

• Swap elements based on the values encountered to sort the array in-place.

• Ensure to handle edge cases like all 0s, all 1s, and all 2s in the array.

Given an array of digits and an integer K, find the maximum number by swapping digits up to K times.

• Sort the digits in non-increasing order to maximize the number.

• Swap the digits to achieve the maximum number within the given number of swaps.

• Handle cases where there are repeating digits and leading zeros.

Move all zeroes to the end of an unsorted array while maintaining the order of non-zero elements.

• Iterate through the array and keep track of the index to place non-zero elements.

• Once all non-zero elements are placed, fill the rest of the array with zeroes.

• Ensure to maintain the relative order of non-zero elements.

• Example: Input: [0, 1, -2, 3, 4, 0, 5, -27, 9, 0], Output: [1, -2, 3, 4, 5, -27, 9, 0, 0, 0]

Given a preorder traversal of a BST, construct the BST and return its inorder traversal.

• Create a binary search tree from the preorder traversal array

• Return the inorder traversal of the constructed BST

• Ensure each element in the array is distinct

To delete the middle element of a linked list, find the middle element using slow and fast pointers, then remove it by adjusting the pointers.

• Use slow and fast pointers to find the middle element

• Adjust pointers to skip the middle element and connect the surrounding nodes

• Free the memory of the deleted node

Multi-programming involves running multiple programs on a single processor, while multi-tasking involves running multiple tasks within a single program.

• Multi-programming allows multiple programs to be loaded into memory and executed concurrently, switching between them to utilize processor time efficiently.

• Multi-tasking allows a single program to perform multiple tasks simultaneously, such as running multiple threads or processes within the program.

• Examples of multi-programmi...read more

Classes and structs are both user-defined types in C++, differing mainly in default access levels and intended use cases.

• Default access level: Classes default to private, while structs default to public.

• Inheritance: Classes can be used for encapsulation and inheritance, whereas structs are typically used for plain data structures.

• Use case: Classes are often used for complex data types with behavior, while structs are used for simple data aggregates.

• Example: class MyClass { pr...read more

Object-Oriented Programming (OOP) is a programming paradigm based on objects and classes, promoting code reusability and modularity.

• Encapsulation: Bundling data and methods that operate on the data within one unit (class). Example: A class 'Car' with properties like 'speed' and methods like 'accelerate()'.

• Inheritance: Mechanism to create a new class from an existing class, inheriting its properties and methods. Example: 'ElectricCar' inherits from 'Car'.

• Polymorphism: Ability ...read more