For K=1 TO 20

For K=1 TO 20

AA is an array, and Alen returns the number of elements in the array
Suppose: AA is an array of 10 rows and 1 column
Then for I = 1 to Alen (AA) / 2 is equivalent to for I = 1 to 10 / 2
Suppose: AA is an array of 10 rows and 2 columns
Then for I = 1 to Alen (AA) / 2 is equivalent to for I = 1 to 20 / 2

What do m and K mean and how to convert

M is megabytes. 1m = 1000K. M and K represent the size of mobile resources. By the way, 1000m = 1g

C language, what is constant, what is variable, write variable definition format and symbolic constant definition format

#Define constant name constant value
Constant value in the program can not be changed!
Variable is modified by int double float Boolean and other modifiers. The value of a variable can be assigned an initial value when it is declared, or it can be assigned a value after declaration before use. The general format is
Modifier variable name;
Variable name = initial value;
Or is it
Modifier variable name = initial value;