Make Number of Distinct Characters Equal
<p>You are given two <strong>0-indexed</strong> strings <code>word1</code> and <code>word2</code>.</p>

<p>A <strong>move</strong> consists of choosing two indices <code>i</code> and <code>j</code> such that <code>0 &lt;= i &lt; word1.length</code> and <code>0 &lt;= j &lt; word2.length</code> and swapping <code>word1[i]</code> with <code>word2[j]</code>.</p>

<p>Return <code>true</code> <em>if it is possible to get the number of distinct characters in</em> <code>word1</code> <em>and</em> <code>word2</code> <em>to be equal with <strong>exactly one</strong> move. </em>Return <code>false</code> <em>otherwise</em>.</p>

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

<pre>
<strong>Input:</strong> word1 = &quot;ac&quot;, word2 = &quot;b&quot;
<strong>Output:</strong> false
<strong>Explanation:</strong> Any pair of swaps would yield two distinct characters in the first string, and one in the second string.
</pre>

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

<pre>
<strong>Input:</strong> word1 = &quot;abcc&quot;, word2 = &quot;aab&quot;
<strong>Output:</strong> true
<strong>Explanation:</strong> We swap index 2 of the first string with index 0 of the second string. The resulting strings are word1 = &quot;abac&quot; and word2 = &quot;cab&quot;, which both have 3 distinct characters.
</pre>

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

<pre>
<strong>Input:</strong> word1 = &quot;abcde&quot;, word2 = &quot;fghij&quot;
<strong>Output:</strong> true
<strong>Explanation:</strong> Both resulting strings will have 5 distinct characters, regardless of which indices we swap.
</pre>

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

<ul>
	<li><code>1 &lt;= word1.length, word2.length &lt;= 10<sup>5</sup></code></li>
	<li><code>word1</code> and <code>word2</code> consist of only lowercase English letters.</li>
</ul>
Hash Table; String; Counting
class Solution {
public:
    bool isItPossible(string word1, string word2) {
        int cnt1[26]{};
        int cnt2[26]{};
        int x = 0, y = 0;
        for (char& c : word1) {
            if (++cnt1[c - 'a'] == 1) {
                ++x;
            }
        }
        for (char& c : word2) {
            if (++cnt2[c - 'a'] == 1) {
                ++y;
            }
        }
        for (int i = 0; i < 26; ++i) {
            for (int j = 0; j < 26; ++j) {
                if (cnt1[i] > 0 && cnt2[j] > 0) {
                    if (i == j) {
                        if (x == y) {
                            return true;
                        }
                    } else {
                        int a = x - (cnt1[i] == 1 ? 1 : 0) + (cnt1[j] == 0 ? 1 : 0);
                        int b = y - (cnt2[j] == 1 ? 1 : 0) + (cnt2[i] == 0 ? 1 : 0);
                        if (a == b) {
                            return true;
                        }
                    }
                }
            }
        }
        return false;
    }
};