![graph TD; A-->B; B-->C;](https://www.www.zyiz.net/i/ll/?i=9823fb7b24344aec99c6022649fc5754.jpg?,type_d3F5LXplbmhlaQ,shadow_50,text_Q1NETiBAbTBfNjI3ODAxNzc=,size_20,color_FFFFFF,t_70,g_se,x_16)
学习了常量和变量,“\0”为字符串结束符,