LeetCode : Longest Common Prefix [java]

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

思路：每两个串确定一个最长公共前缀，然后再拿和这个公共前缀和第三个串确定新的最长公共前缀，以此类推。

public class Solution {
	public String longestCommonPrefix(String[] strs) {
		if (strs == null || strs.length == 0) {
			return "";
		}
		if (strs.length == 1) {
			return strs[0];
		}
		String prefix = strs[0];
		for (int i = 1; i < strs.length; i++) {
			prefix = findCommonPrefix(prefix, strs[i]);
			if (prefix.equals("")) {
				return "";
			}
		}
		return prefix;
	}

	private String findCommonPrefix(String str1, String str2) {
		String prefix = "";
		int i = 0;
		while (i < str1.length() && i < str2.length() && str1.charAt(i) == str2.charAt(i)) {
			prefix += str1.charAt(i);
			i++;
		}
		return prefix;
	}
}