C字符串-字符数组 输入输出函数 输入函数 scanf("%s", s) 读入字符串，在第一个空白符(' ‘、'\n’、'\t')处停止，不读入空白符

排序：将杂乱无章的数据，按照一定的方法进行排列的过程叫做排序。 排序的分类 排序大的分类可分为内排序和外排序，不需要访问外存就能进行排序的叫做内

基础知识 基本概念 1 2 3 4 5 6 7 8 9 程序 = 算法 + 数据结构 数据结构是计算机存储、组织数据的方式。 数据结构是指相互之间存在一种或多种特定关系的数据

Petya started to attend programming lessons. On the first lesson his task was to write a simple program. The program was supposed to do the following: in the given string, consisting if uppercase and lowercase Latin letters, it: deletes all the vowels, inserts a character “.” before each consonant, replaces all uppercase consonants with corresponding lowercase ones. Vowels are letters “A”, “O”, “Y”, “E”, “U”, “I”, and the rest are

NPY is learning arithmetic progression in his math class. In mathematics, an arithmetic progression (AP) is a sequence of numbers such that the difference between the consecutive terms is constant.(from wikipedia) He thinks it’s easy to understand,and he found a challenging problem from his talented math teacher: You’re given four integers, $a_1,a_2,a_3,a_4$, which are the numbers of 1,2,3,4 you have.Can you divide these numbers into some Arithmetic