Leetcode Longest Common Prefix Solution.

 Write a function to find the longest common prefix string amongst an array of strings.

If there is no common prefix, return an empty string "".

 

Example 1:

Input: strs = ["flower","flow","flight"]
Output: "fl"

Example 2:

Input: strs = ["dog","racecar","car"]
Output: ""
Explanation: There is no common prefix among the input strings.

 

Constraints:

• 1 <= strs.length <= 200
• 0 <= strs[i].length <= 200
• strs[i] consists of only lower-case English letters.

Python3 Solution:

class Solution:

    def longestCommonPrefix(self, strs):

        strs=sorted(strs,key=len)

        # here we'll take word having min. length

        # because it will have all possible common prefix

        # eg. out="flow"

        out=strs[0]

        # we'll take remaining words in seperate list

        li=strs[1:]

        pre=''

        for i in range(len(out)):

            # delare a counter

            ct=0

            # here we'll take prefix as i.e temp :

            # eg. i=0   i=1       i=2    ...so on..

            #   temp="f" temp="fl"  temp="flo"

            temp=out[0:i+1]

            # here we'll check this temp if matching with other suffixes or not

            for j in li:

                if temp==j[0:i+1]:

                    # if matches then increase counter

                    ct+=1

            # if our prefix(temp) matches to all prefix of word in li

            # then counter(ct) wil be of length of that li

            if ct==len(li):

                # here we'll update our prefix eith temp

                pre=temp

               

        return pre            

 

ob=Solution()

res=ob.longestCommonPrefix(["flower","flow","flight"])

print(res)

*Note: Constraints are not considered.