AppFolio Interview Questions and Answers

A generic swap function swaps two values of any data type.

• The function should take two parameters of any data type.

• Use a temporary variable to store the value of one parameter.

• Assign the value of the second parameter to the first parameter.

• Assign the value of the temporary variable to the second parameter.

Search for an element in a rotated sorted linked list.

• Find the pivot point where the list is rotated.

• Divide the list into two sublists based on the pivot point.

• Perform binary search on the appropriate sublist.

• Handle edge cases such as empty list and list with only one element.

Search an element in a rotated sorted array

• Find the pivot point where the array is rotated

• Divide the array into two sub-arrays based on pivot point

• Perform binary search on the appropriate sub-array

• Repeat until element is found or sub-array size is 1

Find 5 missing numbers in an array of size 95 containing numbers in range 1 to 100.

• Create a boolean array of size 100 and mark the present numbers

• Iterate through the boolean array and find the missing numbers

• Alternatively, use a HashSet to store the present numbers and find the missing ones

Given a Sudoku board, find possible numbers for an empty cell.

• Iterate through empty cells and check possible numbers using row, column, and box constraints.

• Use a set to keep track of possible numbers for each empty cell.

• Return the set of possible numbers for the given empty cell.

Find integer average of 4 unsigned integers without typecasting

• Add all the integers and divide by 4

• Use bit shifting to divide by 4

• Handle overflow by using long long data type

• Use unsigned int data type for input

Code to identify 32 bit or 64 bit architecture of a processor

• Check if the operating system is 32 bit or 64 bit

• If OS is 32 bit, processor is 32 bit

• If OS is 64 bit, check if processor supports 64 bit architecture

• Use CPUID instruction to check if processor supports 64 bit architecture

Convert binary number to base 64 integer

• Divide the binary number into groups of 6 bits

• Convert each group of 6 bits to decimal

• Map the decimal value to the corresponding base 64 character

• Concatenate the base 64 characters to form the final integer