%d is the output input format is an integer, used for int, short int；; %f is a single-precision floating-point output and input format.

Introduction to c language:

C language operators are symbols to explain specific operations and tools to construct C language expressions. C language is extremely rich in operations, except for control statements and input and output, almost all basic operations are handled by operators. In addition to the three common categories of arithmetic operators, relational operators and logical operators, there are some operators used to accomplish special tasks, such as bit operators.