Breadth First Search Algorithm to Compute the Max Width of a Binary Tree

/**
 * class Tree {
 *     public:
 *         int val;
 *         Tree *left;
 *         Tree *right;
 * };
 */
int maxWidthBinaryTree(Tree* root) {
    if (!root) return 0;
    int ans = 0;
    queue<pair<Tree*, int>> Q;
    Q.push({root, 0});
    while (!Q.empty()) {
        auto sz = Q.size();
        int left = INT_MAX;
        int right = -INT_MAX + 1;
        for (int i = 0; i < sz; ++ i) {
            auto pt = Q.front();
            Q.pop();
            auto p = pt.first;
            auto v = pt.second;
            left = min(left, v);
            right = max(right, v);
            if (p->left) {
                Q.push({p->left, v * 2});
            }
            if (p->right) {
                Q.push({p->right, v * 2 + 1});
            }            
        }
        ans = max(ans, right - left + 1);
    }
    return ans;
}

# class Tree:
#     def __init__(self, val, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def maxWidthBinaryTree(self, root):
        if root is None:
            return 0
        q = [(root, 0)]
        ans = 0
        while len(q) > 0:
            sz = len(q)
            left = float("inf")
            right = float("-inf")
            for i in range(sz):
                p = q.pop(0)
                if p[0].left:
                   q.append((p[0].left, p[1] * 2)) 
                if p[0].right:
                   q.append((p[0].right, p[1] * 2 + 1))
                left = min(left, p[1])
                right = max(right, p[1])
            ans = max(ans, right - left + 1)
        return ans