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.

class Solution {
    public String longestCommonPrefix(String[] strs) {
        if(strs.length==0) return "";
        String prefix=strs[0];
        for(int i=0;i<strs.length;i++)
        {
            while(strs[i].indexOf(prefix)!=0)
            {
                prefix=prefix.substring(0,prefix.length()-1);
                
            }
        }
        return prefix;
    }
}