# include & ltstdio.h & gt
# include & ltconio.h & gt
# include & ltprocess.h & gt// main interface
int jm()
{
int x； Printf ("This is a simple calculator, which can complete the operations of+,-,*,/of two numbers \ n");
printf(" = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = \ n ")；
Printf ("\ t \ t * * * * * * main menu * * * * * * * \ n ");
Printf( "\t\t 1, addition \ n ");
Printf( "\t\t2, subtraction \ n ");
Printf( "\t\t3, multiplication \ n ");
Printf( "\t\t4, division operation \ n ");
Printf( "\t\t5，exit \ n ")；
printf(" = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = \ n ")；
Printf ("Please enter the operation to be performed (the data entered is between 1~5) \ n");
scanf( "%d "，& ampx)； If (x! = 1。 & ampx！ = 2 & amp& ampx！ = 3 & amp& ampx！ = 4 & amp& ampx！ =5 )// Control the input to ensure the input is correct.
{
Printf ("You typed it wrong! Please re-enter \ n ");
fflush(stdin)； //Add this sentence to empty the input buffer. Otherwise, the characters will remain in the buffer.
scanf( "%d "，& ampx)；
} returns x;
}//addition function
int jiafa()
{
int a，b，c； Printf ("You are currently adding \ nPlease enter the two data you want to calculate (please separate the two numbers with spaces when entering) \ n");
Scanf( "%d%d ",&i, & b);
c = a+b； Return to c;
}//subtraction function
Int jianfa ()
{
int a，b，c； Printf ("You are currently performing subtraction \ nPlease enter the two data you want to calculate (please separate the two numbers with spaces when entering) \ n");
Scanf( "%d%d ",&i, & b);
c = a-b； Return to c;
}//Multiplication function
Int Chengfa ()
{
int a，b，c； Printf ("You are currently performing multiplication \ nPlease enter two data to be calculated (please separate the two numbers with spaces when entering) \ n");
Scanf( "%d%d ",&i, & b);
c = a * b； Return to c;
}//division operation function
Floating chufa ()
{
Floating a, b, c; Printf ("You are currently performing division \ nPlease enter two data to be calculated (please separate the two numbers with spaces when entering) \ n");
Scanf( "%d%d ",&i, & b);
c = a/b； Return to c;
}//main function
int main()
{
int x； x = JM()； And (x! = 5 )
{
Switch (x)
{
Case 1:
Printf ("Result: %d\n "，jiafa())；
Break;
Case 2:
Printf ("Result: %d\n "，jianfa())；
Break;
Case 3:
Printf ("Result: %d\n ",Chengfa ());
Break;
Case 4:
Printf ("Result: %f\n "，chufa())；
Break;
} printf ("\ t \ t \ tpress any key to return to the main menu! \ n ")；
getch()；
System ("CLS"); x = JM()；
If (x == 5)
Printf ("Welcome to use this software! Thank you. Bye! ”);
}}