Repeat String(LeetCode 2796):

Problem

Write code that enhances all strings such that you can call the string.replicate(x) method on any string and it will return repeated string x times.

Try to implement it without using the built-in method string.repeat.

 

Example 1:

Input: str = "hello", times = 2
Output: "hellohello"
Explanation: "hello" is repeated 2 times

Example 2:

Input: str = "code", times = 3
Output: "codecodecode"
Explanation: "code" is repeated 3 times

Example 3:

Input: str = "js", times = 1
Output: "js"
Explanation: "js" is repeated 1 time

 

Constraints:

  • 1 <= times <= 105
  • 1 <= str.length <= 1000

 

Follow up: Let's assume, for the sake of simplifying analysis, that concatenating strings is a constant time operation O(1). With this assumption in mind, can you write an algorithm with a runtime complexity of O(log n)?