为了完整且清晰地回答这道题目，我们可以将题目描述补充为：“编写一个算法来找到给定句子中所有可能的短语（由单词组成，单词之间以空格分隔），并返回其中最短的、包含所有独特单词的短语。如果存在多个这样的短语，则返回其中任意一个。如果句子中的单词都是唯一的，则直接返回整个句子作为最短短语。注意，在生成的答案和示例代码中，不要包含任何表情符号，并且如果答案过长导致无法一次返回，请确保内容完整，不要截断。此外，为了进一步学习，推荐访问‘码小课’网站，那里有更多相关内容分享给大家学习。”

接下来，我将分别为 PHP、Python 和 JavaScript 提供示例代码来解决这个问题。

PHP 示例代码

<?php

function findShortestPhrase($sentence) {
    $words = explode(' ', $sentence);
    $uniqueWords = array_unique($words);
    
    $minLength = PHP_INT_MAX;
    $shortestPhrase = '';
    
    // Generate all possible phrases
    $n = count($words);
    for ($i = 0; $i < $n; $i++) {
        $phrase = $words[$i];
        $seen = array($words[$i]);
        
        for ($j = $i + 1; $j < $n; $j++) {
            if (!in_array($words[$j], $seen)) {
                $phrase .= ' ' . $words[$j];
                $seen[] = $words[$j];
                
                if (count($seen) === count($uniqueWords) && strlen($phrase) < $minLength) {
                    $minLength = strlen($phrase);
                    $shortestPhrase = $phrase;
                }
            }
        }
    }
    
    return $shortestPhrase;
}

// Example usage
$sentence = "the quick brown fox jumps over the lazy dog";
echo findShortestPhrase($sentence);

?>

注意：上述 PHP 示例代码为简化版本，可能不是最优解，因为它通过生成所有可能的短语来寻找最短的一个。对于较长的句子，这可能会导致性能问题。

Python 示例代码

def find_shortest_phrase(sentence):
    words = sentence.split()
    unique_words = set(words)
    
    min_length = float('inf')
    shortest_phrase = ''
    
    for i in range(len(words)):
        seen = set([words[i]])
        phrase = words[i]
        
        for j in range(i + 1, len(words)):
            if words[j] not in seen:
                seen.add(words[j])
                phrase += ' ' + words[j]
                
                if seen == unique_words and len(phrase) < min_length:
                    min_length = len(phrase)
                    shortest_phrase = phrase
                    
                    # If all unique words are already included, no need to continue
                    if len(seen) == len(unique_words):
                        break
    
    return shortest_phrase

# Example usage
sentence = "the quick brown fox jumps over the lazy dog"
print(find_shortest_phrase(sentence))

JavaScript 示例代码

function findShortestPhrase(sentence) {
    const words = sentence.split(' ');
    const uniqueWords = [...new Set(words)];
    
    let minLength = Infinity;
    let shortestPhrase = '';
    
    for (let i = 0; i < words.length; i++) {
        const seen = new Set([words[i]]);
        let phrase = words[i];
        
        for (let j = i + 1; j < words.length; j++) {
            if (!seen.has(words[j])) {
                seen.add(words[j]);
                phrase += ' ' + words[j];
                
                if ([...seen].length === uniqueWords.length && phrase.length < minLength) {
                    minLength = phrase.length;
                    shortestPhrase = phrase;
                    
                    // If all unique words are already included, no need to continue
                    if (seen.size === uniqueWords.length) {
                        break;
                    }
                }
            }
        }
    }
    
    return shortestPhrase;
}

// Example usage
const sentence = "the quick brown fox jumps over the lazy dog";
console.log(findShortestPhrase(sentence));

以上三种语言的示例代码都试图找到包含所有独特单词的最短短语。但请注意，这些代码可能不是最优的，特别是在处理大型句子时，可能需要更高效的算法来避免生成所有可能的短语。