[LintCode] #78 Longest Common Prefix

Problem: http://www.lintcode.com/en/problem/longest-common-prefix/

public class Solution {
    /**
     * @param strs: A list of strings
     * @return: The longest common prefix
     */
    public String longestCommonPrefix(String[] strs) {
        if (strs == null || strs.length == 0) {
            return "";
        }
        int minLen = Integer.MAX_VALUE;
        for (String s : strs) {
            minLen = s.length() < minLen ? s.length() : minLen;
        }
        
        for (int i = 0; i < minLen; i++) {
            for (int j = 0; j < strs.length - 1; j++) {
                String s1 = strs[j];
                String s2 = strs[j + 1];
                
                if (s1.charAt(i) != s2.charAt(i)) {
                    return s1.substring(0, i);
                }
            }
        }
        
        return strs[0].substring(0, minLen);
    }
}