excel的列生成算法

echo '<pre>';
$i = 1;
while($i < 703){

    $char1 = floor($i / 26);
    $char2 = $i % 26;
    if($i % 26 == 0)$char1--;
    if($i > 1 && $i % 26 == 1)     echo '<br/>';
    if($char2 == 0) $char2 = 26;

    if($i <= 26){
        echo ' '.chr(64 + $char2). '&emsp;';
    }else{
        echo chr(64 + $char1) . chr(64 + $char2) . '&emsp;';
    }

    $i++;
}
echo '</pre>';

/**
 * 根据当前列号,返回列字符
 * @param int $i
 * @return string
 */
function get_excel_row_name($i){

    $char1 = floor($i / 26);
    $char2 = $i % 26;
    if($i % 26 == 0) $char1--;
    if($char2 == 0) $char2 = 26;

    if($i <= 26){
        return chr(64 + $char2);
    }else{
        return chr(64 + $char1) . chr(64 + $char2);
    }

}