Longest Common Prefix Leetcode Solution

In this post, we are going to solve the Longest Common Prefix Leetcode Solution problem of Leetcode. This Leetcode problem is done in many programming languages like C++, Java, and Python.

Table of Contents

Problem

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 lowercase English letters.

Now, let’s see the leetcode solution of Longest Common Prefix Leetcode Solution.

Longest Common Prefix Leetcode Solution in Python

class Solution:
    def longestCommonPrefix(self, strs):
        if len(strs) == 0:
            return ""
        commonPrefix = strs[0]
        for string in strs:
            commonPrefix = self.findPrefix(commonPrefix,string)

        return commonPrefix

    def findPrefix(self,prefix, string):
        while prefix is not "":
            
            if string.startswith(prefix):
                
                return prefix
            else:
                prefix = prefix[:-1]

        return ""

Longest Common Prefix Leetcode Solution in CPP

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) 
    {
        if (strs.size() == 0)
            return "";
        int maxL = strs[0].length();
        bool match = true;
        int j = 0;
        for (int i = 1; i < strs.size(); i++)
        {
            if ((strs[i]).length() == 0 || (strs[i])[0] != (strs[0])[0])
                return "";
            while (match && j < maxL && j < strs[i].length())
            {
                match = ((strs[i])[j] == (strs[0])[j]);
                j++;
            }
            if (!match)
                maxL = j - 1;
            if (strs[i].length() < maxL)
                maxL = strs[i].length();
            j = 0;
            match = true;
        }
        return strs[0].substr(0, maxL);
    }
};

Longest Common Prefix Leetcode Solution in Java

class Solution {
    public String longestCommonPrefix(String[] strs) {
        if(strs.length == 0){
            return "";
        }
        String pref = strs[0];
        for(String s : strs){
            int len = Math.min(pref.length(), s.length());
            for(int i = len; i >= 0; i--){
                if(pref.indexOf(s.substring(0, i)) == 0){
                    pref = s.substring(0, i);
                    break;
                }
            }
        }
        return pref;
    }
}

Note: This problem Longest Common Prefix is generated by Leetcode but the solution is provided by Chase2learn This tutorial is only for Educational and Learning purposes.

NEXT: 3Sum Leetcode Solution