其实只是计数排序而已🌶

堆排序，优先队列，算法本质上都是一样的。

其实快排和冒泡有着这样那样的关系哦

你知道冒泡排序有几种写…咳咳…优化方法吗

小题目引出大问题,kmp算法，简单的快速字符串匹配

这是一个寻找回文子串的算法，时间复杂度为线性的。

Write a program to solve a Sudoku puzzle by filling the empty cells.

A sudoku solution must satisfy all of the following rules:

Each of the digits 1-9 must occur exactly once in each row.
Each of the digits 1-9 must occur exactly once in each column.
Each of the the digits 1-9 must occur exactly once in each of the 9 3x3 sub-boxes of the grid.
Empty cells are indicated by the character ‘.’

Write a program to find the n-th ugly number.

Ugly numbers are positive integers which are divisible by a or b or c.

Computer Networking:A Top-Down approach chapter 3 lab

Given a binary tree

1
2
3
4
5
6

struct Node {
  int val;
  Node *left;
  Node *right;
  Node *next;
}

Populate each next pointer to point to its next right node. If there is no next right node, the next pointer should be set to NULL.

Initially, all next pointers are set to NULL.