Today, I will share the summary of key points for multiple-choice questions in C language for Computer Level 2 (Part Six).
The content is as follows:
121、In C, bitwise operations can only be applied to integers or character data, and cannot be applied to other types of data.
122、A file pointer is actually a pointer to a structure type, and the general form of defining a file pointer is:FILE* pointer variable identifier,the fscanf function can only read formatted input from text files, and the input object is the data from the text file on disk.
123、The entity integrity of a relationship requires that the relationship cannot be empty, which is the primary key attribute.
124、The worst-case time complexity of heap sort is O(n log2n).
125、The number of nodes in a tree equals the sum of the degrees of all nodes in the tree plus one.N=n0+n1+n2+1
126、When a function is called, if it directly or indirectly calls itself, it is called recursive function calling. In the process of calling f1 function, if it calls f2 function, and in the process of calling f2 function, it calls f1 function, it is an indirect call.
127、If a binary tree has no leaf nodes, it is an empty binary tree..
128、When the front pointer and the rear pointer are the same, the circular queue is either full or empty.
129、The condition for an empty linked stack is: top=bottom=NULL.
130、All linear structures can adopt a sequential storage structure.
131、White-box testing methods include: logical coverage testing, basic path testing, etc. Boundary value analysis belongs to black-box testing.
132、The main features of object-oriented programming are: encapsulation, abstraction, inheritance, unique identification, polymorphism, and good module independence.
133、Software test cases include: input data and expected output results.
134、A binary file can be read from the end first, while a sequential file cannot.
135、At the end of the program, the fclose function should be used to close the opened file.
136、FILE can be used to define a file pointer pointing to a binary file.
137、Some nonlinear structures can also use sequential storage structures, for example, a complete binary tree can adopt a sequential storage structure.
138、The four main functions of an operating system are: process management, storage management, device management, and file management.
139、Computer operating systems have four characteristics: concurrency, sharing, asynchrony, and virtualization.
140、The original code, inverse code, and complement of a positive integer are the same.
In binary, negative numbers are represented in the form of complements..
The rule for converting original code to inverse code: the sign bit remains unchanged, and the value bits are inverted bit by bit.
The rule for converting original code to complement code: the sign bit remains unchanged, the value bits are inverted bit by bit, and add 1 at the end.
All the above content is a personal summary; if there are any errors, please correct me.
Thank you for your support, and I wish you success in your exams
