Question

我有一个带有ID字段的数据库和一个引用具有id的另一个元组的引用字段。

table  
id | ref   
1  | null
2  | null
3  | 1
4  | 1
5  | 1
6  | 4
7  | 6

我想验证一个给定的数组，看看每个元素是否有n-1个元素值作为参考。如果链被破坏......数组不会验证。

例如：array(1,4,6,7)，ref(7) = 6，ref(6)=4和ref(4)=1

时验证{{1}}

Answer 1

$source = [1 => null, 2 => null, 3 => 1, 4 => 1, 5 => 1, 6 => 4, 7 => 6];

$a = [1, 4, 6, 7];
$b = [1, 2, 3];

function validate($source, $check) {
    $thisNum = array_shift($check);
    //This checks the first number, which must not have a ref, it will have NULL value in source array.
    if ($source[$thisNum] != NULL) {
        return false;
    }
    do {
        $nextNum = array_shift($check);
        //This checks that the next number in the list has the ref of the previous number in the source array
        if ($source[$nextNum] !== $thisNum) {
            return false;
        }
        //This is so the next check can use the current next num as the current num to check
        $thisNum = $nextNum;
    } while (count($check));
    //If we haven't failed yet, it must be good!
    return true;
}

var_dump(validate($source, $a));
var_dump(validate($source, $b));

结果是：

boolean true
boolean false

TBH：我几乎没有使用do-while而不是while，但我相信这里需要它，所以你总是可以进行第一次检查。此函数不验证您的数组至少有2个条目是函数的要求，因此请添加该函数。

检查数组元素以查看n-1值是否在数据库中作为参考

1 个答案: