14. Longest Common Prefix

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:

["flower","flow","flight"]

Output:

 "fl"

Example 2:

Input:

["dog","racecar","car"]

Output:

 ""

Explanation:

 There is no common prefix among the input strings.

Note:

All given inputs are in lowercase letters a-z.

 


class Solution {

    /**
     * @param String[] $strs
     * @return String
     */
    function longestCommonPrefix($strs) {
        if(empty($strs)){
            return "";
        }
        $result = "";
        for($i = 0; $i < strlen($strs[0]); $i ++){
            $cur = $strs[0][$i];
            foreach ($strs as $s){
                if($s[$i] != $cur){
                    return $result;
                }
            }
            $result.= $cur;
        }
        return $result;
        
    }
}

 

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