leetcode--Longest Common Prefix

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

public class Solution {
    public String longestCommonPrefix(String[] strs) {
        String prefix = "";
		int length = strs.length;
		if(length > 0){
			prefix = strs[0];
			int prefixLength = strs[0].length();
			for(int i = 1; i < length; ++i){
				int k = 0;
				int strLength = strs[i].length();
				for(int j = 0; j < Math.min(prefixLength, strLength); ++j){
					if(prefix.charAt(j) == strs[i].charAt(j))
						++k;
					else
						break;
				}
				prefix = strs[i].substring(0, k);
				prefixLength = k;
	            if( k == 0)
	                break;
			}
		}
		return prefix;  
    }
}