xinyu04

摘要： You are given a perfect binary tree where all leaves are on the same level, and every parent has two children. The binary tree has the following defin 阅读全文

摘要： You are given two binary trees root1 and root2. Imagine that when you put one of them to cover the other, some nodes of the two trees are overlapped w 阅读全文

摘要： Given an m x n integer matrix matrix, if an element is $0$, set its entire row and column to $0$'s. You must do it in place. Solution 做法并不难，但如果考虑常数空间复 阅读全文

摘要： Design a stack that supports push, pop, top, and retrieving the minimum element in constant time. Implement the MinStack class: MinStack() initializes 阅读全文