leetcode009--a common prefix of two strings

First, the original question

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

Second, Chinese

Write a function to find the longest public prefix in an array of strings.

Iii. Examples

str1 = "Abcmmm" str2 = "abchhhh" Its common string is ABC

Iv. train of Thought

The first step is to find the smallest length of the string, and then find the shortest most common prefix compared to its string.

v. Procedures

Package Leetcode;

public class Leetcode010 {

	private static int longprefixnum;

	public static void Main (string[] args) {
		System.out.println (longestcommonprefix ("Abcduuuu", "Abcnmwewe"));
	
	/**
	 * @param str1  string 1
	 * @param str2  string 2
	 * @return returns the longest common prefix for a string/public
	static String Longestcommonprefix (String str1, String str2) {
		if (str1 = = NULL | | str1.length () < 0 | | str2 = NULL | | str2 . Length () < 0) {return
			null;
		}
		int len1 = Str1.length ();
		int len2 = Str2.length ();
		Longprefixnum = 0;
		
		if (Len1 > Len2) {for
			(int i = 0; i < len2; i++) {
				if (Str1.charat (i) = = Str2.charat (i)) {
					longprefixnum+ +;
				} else{break;}}}
		else{for
			(int i = 0; i < len1 i++) {
				if (Str1.charat (i) = = Str2.charat (i)) {
					longprefixnum++;
				} else{break
		;
		
		}}} Return str1.substring (0, Longprefixnum);
	}

--------------------------Output--------------------------------

Abc