<p>You are given a <strong>0-indexed</strong> string <code>s</code>. You are also given a <strong>0-indexed</strong> string <code>queryCharacters</code> of length <code>k</code> and a <strong>0-indexed</strong> array of integer <strong>indices</strong> <code>queryIndices</code> of length <code>k</code>, both of which are used to describe <code>k</code> queries.</p>

<p>The <code>i<sup>th</sup></code> query updates the character in <code>s</code> at index <code>queryIndices[i]</code> to the character <code>queryCharacters[i]</code>.</p>

<p>Return <em>an array</em> <code>lengths</code> <em>of length </em><code>k</code><em> where</em> <code>lengths[i]</code> <em>is the <strong>length</strong> of the <strong>longest substring</strong> of </em><code>s</code><em> consisting of <strong>only one repeating</strong> character <strong>after</strong> the</em> <code>i<sup>th</sup></code> <em>query</em><em> is performed.</em></p>

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

<pre>
<strong>Input:</strong> s = &quot;babacc&quot;, queryCharacters = &quot;bcb&quot;, queryIndices = [1,3,3]
<strong>Output:</strong> [3,3,4]
<strong>Explanation:</strong> 
- 1<sup>st</sup> query updates s = &quot;<u>b<strong>b</strong>b</u>acc&quot;. The longest substring consisting of one repeating character is &quot;bbb&quot; with length 3.
- 2<sup>nd</sup> query updates s = &quot;bbb<u><strong>c</strong>cc</u>&quot;. 
  The longest substring consisting of one repeating character can be &quot;bbb&quot; or &quot;ccc&quot; with length 3.
- 3<sup>rd</sup> query updates s = &quot;<u>bbb<strong>b</strong></u>cc&quot;. The longest substring consisting of one repeating character is &quot;bbbb&quot; with length 4.
Thus, we return [3,3,4].
</pre>

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

<pre>
<strong>Input:</strong> s = &quot;abyzz&quot;, queryCharacters = &quot;aa&quot;, queryIndices = [2,1]
<strong>Output:</strong> [2,3]
<strong>Explanation:</strong>
- 1<sup>st</sup> query updates s = &quot;ab<strong>a</strong><u>zz</u>&quot;. The longest substring consisting of one repeating character is &quot;zz&quot; with length 2.
- 2<sup>nd</sup> query updates s = &quot;<u>a<strong>a</strong>a</u>zz&quot;. The longest substring consisting of one repeating character is &quot;aaa&quot; with length 3.
Thus, we return [2,3].
</pre>

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

<ul>
	<li><code>1 &lt;= s.length &lt;= 10<sup>5</sup></code></li>
	<li><code>s</code> consists of lowercase English letters.</li>
	<li><code>k == queryCharacters.length == queryIndices.length</code></li>
	<li><code>1 &lt;= k &lt;= 10<sup>5</sup></code></li>
	<li><code>queryCharacters</code> consists of lowercase English letters.</li>
	<li><code>0 &lt;= queryIndices[i] &lt; s.length</code></li>
</ul>

class Solution {
private:
    struct Node {
        int maxLen, prefixLen, suffixLen;
        Node(int val = 0) : maxLen(val), prefixLen(val), suffixLen(val) {}
    };
    vector<Node> segTree;
    string s;

    void build(int node, int start, int end) {
        if (start == end) {
            segTree[node] = Node(1);
            return;
        }
        int mid = (start + end) / 2;
        build(2 * node, start, mid);
        build(2 * node + 1, mid + 1, end);
        combine(node, start, end);
    }

    void combine(int node, int start, int end) {
        int mid = (start + end) / 2;
        int left = 2 * node, right = 2 * node + 1;
        
        Node& parent = segTree[node];
        Node& leftChild = segTree[left];
        Node& rightChild = segTree[right];

        parent.maxLen = max(leftChild.maxLen, rightChild.maxLen);
        parent.prefixLen = leftChild.prefixLen;
        parent.suffixLen = rightChild.suffixLen;

        if (s[mid] == s[mid + 1]) {
            int borderLen = leftChild.suffixLen + rightChild.prefixLen;
            parent.maxLen = max(parent.maxLen, borderLen);
            
            if (leftChild.prefixLen == mid - start + 1)
                parent.prefixLen += rightChild.prefixLen;
            if (rightChild.suffixLen == end - mid)
                parent.suffixLen += leftChild.suffixLen;
        }
    }

    void update(int node, int start, int end, int idx, char newChar) {
        if (start == end) {
            s[idx] = newChar;
            segTree[node] = Node(1);
            return;
        }

        int mid = (start + end) / 2;
        if (idx <= mid)
            update(2 * node, start, mid, idx, newChar);
        else
            update(2 * node + 1, mid + 1, end, idx, newChar);

        combine(node, start, end);
    }

public:
    vector<int> longestRepeating(string str, string queryCharacters, vector<int>& queryIndices) {
        s = str;
        int n = s.length();
        segTree.resize(4 * n);
        build(1, 0, n - 1);

        vector<int> results;
        for (int i = 0; i < queryCharacters.size(); ++i) {
            update(1, 0, n - 1, queryIndices[i], queryCharacters[i]);
            results.push_back(segTree[1].maxLen);
        }
        return results;
    }
};
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