<p>Given a <code>pattern</code> and a string <code>s</code>, find if <code>s</code>&nbsp;follows the same pattern.</p>

<p>Here <b>follow</b> means a full match, such that there is a bijection between a letter in <code>pattern</code> and a <b>non-empty</b> word in <code>s</code>. Specifically:</p>

<ul>
	<li>Each letter in <code>pattern</code> maps to <strong>exactly</strong> one unique word in <code>s</code>.</li>
	<li>Each unique word in <code>s</code> maps to <strong>exactly</strong> one letter in <code>pattern</code>.</li>
	<li>No two letters map to the same word, and no two words map to the same letter.</li>
</ul>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">pattern = &quot;abba&quot;, s = &quot;dog cat cat dog&quot;</span></p>

<p><strong>Output:</strong> <span class="example-io">true</span></p>

<p><strong>Explanation:</strong></p>

<p>The bijection can be established as:</p>

<ul>
	<li><code>&#39;a&#39;</code> maps to <code>&quot;dog&quot;</code>.</li>
	<li><code>&#39;b&#39;</code> maps to <code>&quot;cat&quot;</code>.</li>
</ul>
</div>

<p><strong class="example">Example 2:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">pattern = &quot;abba&quot;, s = &quot;dog cat cat fish&quot;</span></p>

<p><strong>Output:</strong> <span class="example-io">false</span></p>
</div>

<p><strong class="example">Example 3:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">pattern = &quot;aaaa&quot;, s = &quot;dog cat cat dog&quot;</span></p>

<p><strong>Output:</strong> <span class="example-io">false</span></p>
</div>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= pattern.length &lt;= 300</code></li>
	<li><code>pattern</code> contains only lower-case English letters.</li>
	<li><code>1 &lt;= s.length &lt;= 3000</code></li>
	<li><code>s</code> contains only lowercase English letters and spaces <code>&#39; &#39;</code>.</li>
	<li><code>s</code> <strong>does not contain</strong> any leading or trailing spaces.</li>
	<li>All the words in <code>s</code> are separated by a <strong>single space</strong>.</li>
</ul>

class Solution {
public:
    bool wordPattern(string pattern, string s) {
      unordered_map<unsigned long, char> hashmap;
    unordered_map<char, unsigned long> hashmap2;
    unsigned long hash = 5381;
    int beg = 0;
    int end = 0;
    int count;
    for(count = 0; count < pattern.length(); count++){
        while(true){
            if(s[end] == ' ' || s[end] == '\0')
                break;
            end++;
        }

        if(beg == end)
            break;

        unsigned long val = hash;

        for(int i = beg; i < end; i++){
           val = ((val << 5) + val) + s[i];
        }

        if(hashmap.find(val) == hashmap.end()){
            if(hashmap2.find(pattern[count]) == hashmap2.end())
               {
                    hashmap.insert({val, pattern[count]});
                    hashmap2.insert({pattern[count], val});
               }
            else
                return false;
        }
        else{
            char comp = hashmap[val];
            if(comp != pattern[count])
                return false;
        }
        end++;
        beg = end;
    }
    if(count != pattern.length() || end < s.length())
        return false;
    return true;
    }
};
7900