## 题目

Given n balloons, indexed from 0 to n-1. Each balloon is painted with a
number on it[……]

# 探索最长回文串性质

abcd???
|
center

abcdcba
|
center

## 求两个集合/数组的交集

A = [9, 1, 4, 2, 5] k个整数
B = [3, 1, 8, 7, 6, 5] n个整数
Intersection => [1, 5]

# 推导

1-2-3-4
|___|


In[1]:=Reduce[Mod[n – 1, 3] ==[……]

## Fraction to Recurring Decimal正则表达式、循环小数复习

Given two integers representing the numerator and denominator of a fraction, ret[……]

# 题目

Given an array of size n, find the majority element. The m[……]

# 题目

Given an unsorted array, find the maximum difference between the successive elements in its sort[……]