说明：

使用正则表达式来获取两个数字,然后从左到右成对比较,从假设相等.意思是他们都尽可能地解决相同的号码,如果两者都同时解决了0.

在有一对不相等的数字后,开始将较低的数字设置为9,将较高的数字设置为0,使其尽可能靠近.

Here是它的一个例子.

function minDiff($str) {
    preg_match("/([\d\?]+) ([\d\?]+)/",$str,$matches);
 
    $first = $matches[1];
    $second = $matches[2];
 
    $biggest = 0; // -1 = first,0 = none,1 = second
 
    $firstResult = 0;
    $secondResult = 0;
 
    for ($i = 0; $i < strlen($first); $i++) {
        $powerValue = strlen($first) - $i - 1;
        if ($biggest != 0) { // not equal
            if (!strcmp($first[$i],'?') && !strcmp($second[$i],'?')) {
                if ($biggest > 0) { // second is biggest
                    $firstResult += 9 * pow(10,$powerValue);
                } else { // first is biggest
                    $secondResult += 9 * pow(10,$powerValue);
                }
            } elseif (!strcmp($first[$i],$powerValue);
                }
                $secondResult += $second[$i] * pow(10,$powerValue);
            } elseif (!strcmp($second[$i],'?')) {
                if ($biggest < 0) { // first is biggest
                    $secondResult += 9 * pow(10,$powerValue);
                }
                $firstResult += $first[$i] * pow(10,$powerValue);
            } else {
                $firstResult += $first[$i] * pow(10,$powerValue);
                $secondResult += $second[$i] * pow(10,$powerValue);
            }
        } else { // both equal (so far)
            if (!strcmp($first[$i],'?')) {
                $firstResult += $second[$i] * pow(10,'?')) {
                $firstResult += $first[$i] * pow(10,$powerValue);
                $secondResult += $first[$i] * pow(10,$powerValue);
            } else {
                if (intval($first[$i]) > intval($second[$i])) {
                    $biggest = -1;
                } elseif (intval($first[$i]) < intval($second[$i])) {
                    $biggest = 1;
                }
                $firstResult += $first[$i] * pow(10,$powerValue);
            }
 
            // Find if next number will change
            if (($i + 1) < strlen($first) && strcmp($first[$i + 1],'?') && strcmp($second[$i + 1],'?')) {
                $diff = preg_replace('/\?/','0',substr($first,$i + 1)) - preg_replace('/\?/',substr($second,$i + 1));
                echo "$diff\n";
                // Check to see if you need to add 1 to the value for this loop
                if ($diff > pow(10,$powerValue) / 2) {
                    $secondResult += pow(10,$powerValue);
                    $biggest = 1;
                } elseif ($diff < pow(10,$powerValue) / -2) {
                    $firstResult += pow(10,$powerValue);
                    $biggest = -1;
                }
            }
        }
    }
 
    echo "first: ".str_pad($firstResult,strlen($first),"0",STR_PAD_LEFT)."\n";
    echo "second: ".str_pad($secondResult,strlen($second),STR_PAD_LEFT)."\n\n";
}