Longest Common Prefix

public static String longestCommonPrefix( String[] strs ) {
    if( strs == null || strs.length == 0 ) return "";
    if( strs.length == 1 ) return strs[0];
    int pos = 0;
    while( true ) {
        for( int i = 1; i < strs.length; ++i )
            if( strs[i-1].length() <= pos || strs[i].length() <= pos || 
                strs[i].charAt( pos ) != strs[i-1].charAt( pos ) )
                return strs[0].substring( 0, pos );
        ++pos;
    }
}