Question

假设我有五个元素的数组。我需要找到那些经常重复并按顺序排列的那些。

$array = array('one','five','five','five','four');

预期输出为：five，因为它是最大的相等元素序列。我如何找到这些元素或者比较它们的值，以便我可以计算出哪些元素重复了？

foreach ($array as $element) { #find repeating elements }

Answer 1

尝试这种方式。我认为这将满足您的需求！

$array = array('one','five','five','five','four');
$counts = array_count_values($array);
$max = 0; $key = '';
foreach($counts as $k=>$v){
    if($v > $max)
    {
        $max = $v;
        $key = $k;
    }
}
echo $key;

Answer 2

有点像粗野的方法。有点像kingkero引用。例如：

$array = array('one','one','one','five','five','five','five','five','four','four', 'one','four');
$prev = '';
$sequences = array();

// group them
foreach($array as $value) {
    if(!isset($sequences[$value])) {
        $sequences[$value][] = 0;
        $prev = $value;
    }

    if($prev == $value) {
        $val = array_pop($sequences[$value]) + 1;
        $sequences[$value][] = $val;
    } else {
        $prev = $value;
        $sequences[$value][] = 1;
    }

}

序列将如下所示：

Array
(
    [one] => Array
        (
            [0] => 3
            [1] => 1
        )

    [five] => Array
        (
            [0] => 5
        )

    [four] => Array
        (
            [0] => 2
            [1] => 1
        )

)

// identify
$data['key_with_the_most'] = '';
$data['consecutive_pattern'] = 0;
foreach($sequences as $key => $value) {
    if(max($value) > $data['consecutive_pattern']) {
        $data['consecutive_pattern'] = max($value);
        $data['key_with_the_most'] = $key;
    }
}

echo '<pre>';
print_r($data);

$data输出到：

Array
(
    [key_with_the_most] => five
    [consecutive_pattern] => 5
)

Answer 3

$array  = ['a','b','b','c'];
$counts = array_count_values($array);
arsort($counts);
print key($counts);

输出：

Answer 4

假设输入可以有多个序列且项目数相同：

<?php
$array = ['a','a','b','b','c','b'];

$grouped = [];
$last = null;
$i = 0;
foreach($array as $k => $v) {
    if($last !== $v)
        $i = $k;
    $grouped[$i][] = $last = $v;
}

print_r($grouped);

$counted_groups = array_map('count', $grouped);
arsort($counted_groups);

print_r($counted_groups);

$max_consecutives = [];
$max_occurences   = current($counted_groups);
$max_counted_keys = array_keys($counted_groups, $max_occurences);
foreach($max_counted_keys as $counted_groups_key)
    $max_consecutives[] =
        [
            'item' => $array[$counted_groups_key],
            'no_repeats' => $max_occurences,
            'from_index' => $counted_groups_key
        ];

print_r($max_consecutives);

输出：

Array
(
    [0] => Array
        (
            [0] => a
            [1] => a
        )

    [2] => Array
        (
            [0] => b
            [1] => b
        )

    [4] => Array
        (
            [0] => c
        )

    [5] => Array
        (
            [0] => b
        )

)
Array
(
    [0] => 2
    [2] => 2
    [4] => 1
    [5] => 1
)
Array
(
    [0] => Array
        (
            [item] => a
            [no_repeats] => 2
            [from_index] => 0
        )

    [1] => Array
        (
            [item] => b
            [no_repeats] => 2
            [from_index] => 2
        )

)

查找数组中最大的相等元素序列

4 个答案: