## PAT(A) 1135. Is It A Red-Black Tree (30)

### 1135. Is It A Red-Black Tree (30)

There is a kind of balanced binary search tree named red-black tree in the data structure. It has the following 5 properties:

## PAT(A) 1134. Vertex Cover (25)

### 1134. Vertex Cover (25)

A vertex cover of a graph is a set of vertices such that each edge of the graph is incident to at least one vertex of the set. Now given a

## PAT(A) 1133. Splitting A Linked List (25)

### 1133. Splitting A Linked List (25)

Given a singly linked list, you are supposed to rearrange its elements so that all the negative values appear before all of the non-negatives, and all the values in [0, K]

## PAT(A) 1132. Cut Integer (20)

### 1132. Cut Integer (20)

Cutting an integer means to cut a K digits long integer Z into two integers of (K/2) digits long integers A and B. For example, after cutting Z = 167334,

## PAT(A) 1127. ZigZagging on a Tree (30)

### 1127. ZigZagging on a Tree (30)

Suppose that all the keys in a binary tree are distinct positive integers. A unique binary tree can be determined by a given pair of postorder and inorder traversal sequences.

## PAT(A) 1126. Eulerian Path (25)

### 1126. Eulerian Path (25)

In graph theory, an Eulerian path is a path in a graph which visits every edge exactly once. Similarly, an Eulerian circuit is an Eulerian path which starts and ends on the same vertex.

## PAT(A) 1125. Chain the Ropes (25)

### 1125. Chain the Ropes (25)

Given some segments of rope, you are supposed to chain them into one rope. Each time you may only fold two segments into loops and chain them into one