ThoughtWorks Quality Assurance Engineer Interview Questions and Answers

The question asks to count the number of occurrences of each character in a given string, ignoring case and wild card characters.

• Convert the string to lowercase to ignore case.

• Remove any wild card characters from the string.

• Create an array of size 26 to store the count of each character.

• Iterate through each character in the string and increment the count in the array accordingly.

• Return the array of counts as the result

HashMap is used for efficient key-value pair storage and retrieval.

• HashMap provides constant time complexity for basic operations like get and put.

• It allows storing unique keys and their corresponding values.

• HashMap is suitable for scenarios where fast lookup is required.

• Other collections like ArrayList or LinkedList have different use cases and performance characteristics.