PHP 如何计算可以从字符串中的字母组成单词的次数？

Question

I wanted to make a function which you can see how many times you can make a random word from a text.

For example:

The text is: Ham followed now ecstatic use speaking exercise may repeated. Himself he evident oh greatly my on inhabit general concern. It allowance prevailed enjoyment in it. Calling observe for who pressed raising his. Can connection instrument astonished unaffected his motionless preference. Announcing say boy precaution unaffected difficulty alteration him.

I want to know how many times you can write the word "potato".

so, I started to make a function (which is not good enough of course):

<?php
$text = "Ham followed now ecstatic use speaking exercise may repeated.
Himself he evident oh greatly my on inhabit general concern. It allowance 
prevailed enjoyment in it. Calling observe for who pressed raising his. Can 
connection instrument astonished unaffected his motionless preference. 
Announcing say boy precaution unaffected difficulty alteration him.";
$word = "Potato";

//function
    function count($text) {
 for ($i = 0; $i <= strlen($text); $i++) {
  if ($text[$i] == "p") {
$p = 0;
$p++;
echo $p; } } }
?>

My question now is: how do you count from now on the number of times you can make the word "potato"?

Thanks for replying.

Answer 1

此函数可帮助您获取paroto在该字符串中使用的次数

echo substr_count($text, $word);

Answer 2

My approach would be to go through the text storing each character in a dictionary where the key is the letter and the value is the number of occurrences in the text. Once you finish processing the text you can calculate how many times you can spell potato

Answer 3

Firstly, you cannot declare count function as it is already declared.

Try this:

function countt($text, $word, $count = 0) {
    $found = '';
    for($i=0; $i<strlen($word);$i++){
        for($j=0; $j<strlen($text);$j++){
            if($word{$i} === $text{$j}){
                $text = substr($text,0,$j).substr($text,$j+1);
                $found.= $word{$i};
                if($found === $word){
                    $count++;
                    return countt($text,$word,$count);
                }
                break;
            }
        }
    }
    return $count;
}

echo countt($text,'potato');//6

Explanation: function finds occurences of each letter of a word in text and removes it from the text. Once it completes new word that is identical to the searched one, it calls this function again with new text, that misses those used letters, until there is no more letters left that could complete another word.

You can play with it here:

http://sandbox.onlinephpfunctions.com/code/ba579be33a82a6abdc0fc285cc4a631186eb7b29