Write a function to find the longest common prefix string amongst an array of strings.

Write a function to find the longest common prefix string amongst an array of strings.

 给定一个String类型数组，要求写一个方法，返回数组中这些字符串的最长公共前缀。

方法一:

import java.util.Scanner;
import java.util.logging.Logger;PortableInterceptor.SYSTEM_EXCEPTION;public class Solution {public static String longestCommonPrefix(String[] strs) {if (strs.length == 0) return "";for (int j = 0; j < strs[0].length(); ++j){ // 纵向扫描for (int i = 1; i < strs.length; ++i){if (j == strs[i].length() ||strs[i].charAt(j) != strs[0].charAt(j))return strs[0].substring(0, j);}}return strs[0];}public static void main(String[] args) {String strs[] = new String[]{"abcdefg","abcef","abcdeabcg"};System.out.println(longestCommonPrefix(strs));
}
}

方法二:

public String longestCommonPrefix(String[] strs) {String result = strs.length==0?"":strs[0];for(int j=0;j<strs.length;j++){result = commonPrefix(result,strs[j]);}return result;}private String commonPrefix(String origin,String target){StringBuffer sb = new StringBuffer();int loop = origin.length()>=target.length()?target.length():origin.length();for(int i=0;i<loop;i++){if(origin.charAt(i) == target.charAt(i)){sb.append(origin.charAt(i));}else{break;}}String();}