Category: c / c++

Design a class to find the kth largest element in a stream. Note that it is the kth largest element in the sorted order, not the kth distinct element. …

For a binary tree T, we can define a flip operation as follows: choose any node, and swap the left and right child subtrees. A binary tree X is …

Given a binary tree, count the number of uni-value subtrees. A Uni-value subtree means all nodes of the subtree have the same value. Example : Input: root = 5 …

In a string S of lowercase letters, these letters form consecutive groups of the same character. For example, a string like S = “abbxxxxzyy” has the groups “a”, “bb”, …

In a town, there are N people labelled from 1 to N. There is a rumor that one of these people is secretly the town judge. If the town …