Longest common prefix

Link: https://leetcode.com/problems/longest-common-prefix/

Solution:

Topics: vertical scan

Intuition
Cute little problem with a couple interesting edge cases. Simple vertical scan will do.

1. If the length of strs is 1, return strs[0].
2. It could be the case that strs are all duplicates so don’t rely on the exit condition to return the result.

Implementation

def longest_pre(strs):
	if len(strs) == 1:
		return strs[0]
	res = ''
		
	for j in range(len(strs[0])):
		for i in range(1, len(strs)):
			if j == len(strs[i]) or strs[0][j] != strs[i][j]:
				return res
		res += strs[0][j]
	return res
 
#time:
#memory:

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