ChiPy Algorithms SIGDescription
Write a function that reverses a string. The input string is given as list of letters.
Do not create a new list, you must do this by modifying the input list in-place with O(1) extra memory.
Can you do it using a loop? Can you do it recursively?
Input: ['H','e','l','l','o']
Output: ['o','l','l','e','H']
Iterative Solution
# Insert solution here
length = len(s)-1
for i in range(0,length-1):
s[i], s[length-i] = s[length-i], s[i]
Recursive Solution
def helper(s, left_idx, right_idx):
if left_idx >= right_idx:
return
temp = s[left_idx]
s[left_idx] = s[right_idx]
s[right_idx] = temp
helper(s, left_idx + 1, right_idx - 1)