擅长:python、mysql、java
<p>你跳过了这一步,如果结果大于10,每隔两位数取两位数之和。来自<a href="http://en.wikipedia.org/wiki/Luhn_algorithm" rel="nofollow">Wikipedia</a>:</p>
<blockquote>
<p>From the rightmost digit, which is the check digit, moving left, double the value of every second digit; if product of this doubling operation is greater than 9 (e.g., 7 * 2 = 14), then sum the digits of the products (e.g., 10: 1 + 0 = 1, 14: 1 + 4 = 5).</p>
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