longest-common-prefix

public class Solution {
    public String longestCommonPrefix(String[] strs) {
        if (strs == null || strs.length == 0) return "";

        for (int prefixLen = 0; prefixLen < strs[0].length(); prefixLen++) {
            char c = strs[0].charAt(prefixLen);
            for (int i = 1; i < strs.length; i++) {
                if ( prefixLen >= strs[i].length() ||
                    strs[i].charAt(prefixLen) != c ) {
                    // Mismatch found
                    return strs[i].substring(0, prefixLen);
                }
            }
        }
        return strs[0];
         
    }
}