Longest Common Prefix

Longest Common Prefix

Mode:-Easy

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.


Time Complexity-o(n*2)
Space Complexity-o(1)

Java Solution

class Solution {
  public String longestCommonPrefix(String[] strs) {
    int len=strs[0].length();
    for(int i=1;i<strs.length;i++){
     if(strs[i].length()<len)  
       len=strs[i].length();
    }
    String ans="";

    for(int i=0;i<len;i++){
      for(int j=0;j<strs.length-1;j++){

        if(strs[j].charAt(i)!=strs[j+1].charAt(i))
        {
        return ans;
        }
      }
        ans+=strs[0].charAt(i);
      
    }
    return ans;
  }
}