Leetcode006 -- find the longest common prefix in the string array

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class test06 {
    /**
     *  Write a function to find the longest common prefix in the string array .
     *  If no common prefix exists , Returns an empty string "".
     *
     *  Example  1：
     *  Input ：strs = ["flower","flow","flight"]
     *  Output ："fl"
     *
     *  Example  2：
     *  Input ：strs = ["dog","racecar","car"]
     *  Output ：""
     *  explain ： Input does not have a common prefix .
     *
     *  Tips ：
     * 1 <= strs.length <= 200
     * 0 <= strs[i].length <= 200
     * strs[i]  It's only made up of lowercase letters 
     *
      * @param args
     */
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] strs = null;
        strs = br.readLine().split(",");

        System.out.println(longestCommonPrefix(strs));

    }

    public static String longestCommonPrefix(String[] strs) {
        if(strs == null || strs.length == 0){
            return "";
        }

        int length = strs[0].length();
        int count = strs.length;
        for(int i=0; i<length; i++){
            char c = strs[0].charAt(i);
            for(int j=1; j<count; j++){
                if(i == strs[j].length() || strs[j].charAt(i)!= c){
                    return strs[0].substring(0,i);
                }
            }
        }
        return strs[0];
    }
}