Is To Lower Case easy or hard?

To Lower Case is classified as an Easy problem. It focuses on basic string traversal and character conversion logic, making it a common introductory exercise for string manipulation.

To Lower Case Python/Java solution

Python uses the built-in method s.lower(), which converts all uppercase letters to lowercase in O(n) time. In Java, the equivalent method is s.toLowerCase(). Both rely on optimized standard library implementations for character transformation.

How to solve To Lower Case in O(n)?

Iterate through the string once and convert uppercase characters to lowercase. Using built-in functions like lower() or toLowerCase() achieves this directly. A manual approach checks if a character lies between 'A' and 'Z' and adds 32 to its ASCII value to convert it.

What is the best approach for To Lower Case?

The built-in string conversion function such as lower() in Python or toLowerCase() in Java is the best approach. It converts every character in a single pass with O(n) time complexity and uses optimized standard library implementations. This approach keeps the code concise and reliable.

Is To Lower Case asked at Google/Amazon/Meta?

To Lower Case is categorized as an easy string manipulation problem and is commonly used for basic screening or warm-up rounds. Similar character processing questions appear in interviews at companies like Amazon, Google, and Meta to test familiarity with string operations.

What data structure is used in To Lower Case?

The problem primarily uses a string or a character array. The algorithm iterates through characters sequentially and either modifies them directly or constructs a new string with converted characters.

What is the time complexity of To Lower Case?

The time complexity is O(n), where n is the length of the string. Each character must be inspected at least once to determine whether it should be converted. Both the built-in method and manual ASCII conversion operate in linear time.

Description Hints 3 Solution Video 22:07

709. To Lower Case

Easy84.8% acceptance3 companies

Given a string s, return the string after replacing every uppercase letter with the same lowercase letter.

Example 1:

Input: s = "Hello"
Output: "hello"

Example 2:

Input: s = "here"
Output: "here"

Example 3:

Input: s = "LOVELY"
Output: "lovely"

Constraints:

1 <= s.length <= 100
s consists of printable ASCII characters.

Asked at 3 companies

Google Microsoft Meta

Topics

String

Hints open one at a time

Hint 1

Most languages support lowercase conversion for a string data type. However, that is certainly not the purpose of the problem. Think about how the implementation of the lowercase function call can be done easily.

Hint 2

Think ASCII!

Hint 3

Think about the different capital letters and their ASCII codes and how that relates to their lowercase counterparts. Does there seem to be any pattern there? Any mathematical relationship that we can use?

22:07

Still stuck?Read 3 approaches, or watch a walkthrough.

Open solution