Leetcode14 longest public prefix

Write a function to find the longest common prefix in the string array .

If no common prefix exists , Returns an empty string  "".

 Input ：strs = ["flower","flow","flight"]
 Output ："fl"

Ideas ： Longitudinal scan

During longitudinal scanning , Go through each column of all strings from front to back , Compare whether the characters on the same column are the same , If the same, continue to compare the next column , If not, the current column no longer belongs to the public prefix , When the part before the front row is the longest public prefix .

public String longestCommonPrefix(String[] strs) {
        if(strs == null || strs.length == 0)
            return "";
        
        for(int i = 0; i < strs[0].length();i++){
            char c = strs[0].charAt(i);
            for(int j = 1; j < strs.length;j++){
                // The length of other strings is less than the length of the first string 
                if(i == strs[j].length() || strs[j].charAt(i) != c)
                    return strs[0].substring(0,i);
            }
        }
        return strs[0];


    }