<p>Given two strings <code>s</code> and <code>t</code>, <em>determine if they are isomorphic</em>.</p>

<p>Two strings <code>s</code> and <code>t</code> are isomorphic if the characters in <code>s</code> can be replaced to get <code>t</code>.</p>

<p>All occurrences of a character must be replaced with another character while preserving the order of characters. No two characters may map to the same character, but a character may map to itself.</p>

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

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">s = &quot;egg&quot;, t = &quot;add&quot;</span></p>

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

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

<p>The strings <code>s</code> and <code>t</code> can be made identical by:</p>

<ul>
	<li>Mapping <code>&#39;e&#39;</code> to <code>&#39;a&#39;</code>.</li>
	<li>Mapping <code>&#39;g&#39;</code> to <code>&#39;d&#39;</code>.</li>
</ul>
</div>

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

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">s = &quot;foo&quot;, t = &quot;bar&quot;</span></p>

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

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

<p>The strings <code>s</code> and <code>t</code> can not be made identical as <code>&#39;o&#39;</code> needs to be mapped to both <code>&#39;a&#39;</code> and <code>&#39;r&#39;</code>.</p>
</div>

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

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">s = &quot;paper&quot;, t = &quot;title&quot;</span></p>

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

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

<ul>
	<li><code>1 &lt;= s.length &lt;= 5 * 10<sup>4</sup></code></li>
	<li><code>t.length == s.length</code></li>
	<li><code>s</code> and <code>t</code> consist of any valid ascii character.</li>
</ul>

class Solution {
public:
    bool isIsomorphic(string s, string t) {
        map <char,int>m1,m2;
        if (s.size()!= t.size()) {
            return false;
        }
        for (int i = 0; i< s.size(); i++) {
            if (m1.find(s[i])!= m1.end())
            {
                if (m1[s[i]] != t[i])
                {
                    return false;
                }
            }
            if (m2.find(t[i])!= m2.end()) 
            {
                if (m2[t[i]] != s[i])
                    {
                        return false;
                    }
                }
            
            else {
            m1[s[i]] = t[i];
            m2[t[i]] = s[i];
        }
}
        return true;
    }
};
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