Problem Statement

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.

Problem Link

Longest Common Prefix - LeetCode

Code

class Solution {
public:
    string longestCommonPrefix(vector<string>& strs) {
        
        int res = 0;
        int minlen = INT_MAX;
        
        for(string str:strs)
        {
            minlen = min(minlen,(int)str.size());    
        }
        int flag = 1;
        for(int i=0;i<minlen;i++)
        {
            
            for(int j=0;j<strs.size()-1;j++)
            {
                if(strs[j][i]!=strs[j+1][i])
                {
                    flag = 0;
                    break;
                }
            }
            
            if(!flag)
                break;
            
            else
                res++;
        }
        
        return strs[0].substr(0,res);
        
    }
};