Code:
#include <stdio.h>
/* function prototypes */
int sum( int x, int y );
int subtract( int x, int y );
int mult( int x, int y);
float divide( int x, int y );
int po( int x, int y );
int gcd( int x, int y );
int fact( int x );
/* function main begins program execution */
int main ()
{
int x; /* first variable for function input */
int y; /* second variable for function input */
int z; /* variable for menu selection */
/* menu options given to user */
printf( "Welcome to the math calculator!\n" );
printf( "Select a numerical option from the menu.\n" );
printf( "\n" );
printf( "1 Sum two integers.\n2 Subtract two integers.\n3 Multiply two integers.\n4 Divide two integers." );
printf( "5 Calculate an integer raised to an integer.\n 6 Compute GCD of two integers.\n 7 Factorial of integer.\n" );
printf( "8 Quit Program.\n" );
scanf( "%d", &z ); /* inputs menu option */
/* while loop calls the function, performs the computation, and returns to the menu */
while( z != 8 ) {
switch ( z ){
case ' 1 ' :
printf( "Enter x and y" ); /* prompts user for input values */
scanf( "%d%d", &x, &y ); /* inputs values to x and y */
int a = sum ( x,y ); /* defines sum to a variable */
printf( "Sum is %d.\n", a ); /* outputs sum */
break; /* breaks from switch...case */
case '2' :
printf( "Enter x and y" ); /* same as before */
scanf( "%d%d", &x, &y ); /* same as before */
int b = subtract( x,y ); /* same as before with "sum" replaced as "subtract" */
printf( "Difference is %d.\n", b ); /* same as before with "sum" replaced as "subtract" */
break; /* same as before */
case '3' :
printf( "Enter x and y" );
scanf( "%d%d", &x, &y );
int c = mult( x,y );
printf(" Product is %d.\n", c );
break;
case '4' :
printf( "Enter x and y" );
scanf( "%d%d", &x, &y );
/* ensures denominator is non-zero */
while ( y == 0 ) {
printf( "Please enter non-zero y.\n" );
scanf( "%d", &y );
}
float d = divide( x,y );
printf( "Quotient is %f.\n", d );
break;
case '5' :
printf( "Enter x and y" );
scanf( "%d%d", &x, &y );
int e = po( x,y );
printf( "Power is %d.\n", e );
break;
case '6' :
printf( "Enter x and y" );
scanf( "%d%d", &x, &y );
int j = gcd( x,y );
printf( "GCD is %d.\n", j );
break;
case '7' :
printf( "Enter x" );
scanf( "%d%d", &x );
/* ensures value is non-negative */
while ( x < 0 ) {
printf( "Please enter a non-negative value of x.\n" );
scanf( "%d", & x );
}
int k = fact( x );
printf("Factorial is %d.\n", k );
break;
/* prompts for menu options again */
printf( "Select a numerical option from the menu.\n" );
printf( "\n" );
printf( "1 Sum two integers.\n2 Subtract two integers.\n3 Multiply two integers.\n4 Divide two integers." );
printf( "5 Calculate an integer raised to an integer.\n 6 Compute GCD of two integers.\n 7 Factorial of integer.\n" );
printf( "8 Quit Program.\n" );
scanf( "%d", &z );
}
printf( "Goodbye!\n" );
return 0; /* indicate program ended succesfully */
} /* end function main */
/* function definitions */
/* definition of sum */
int sum( int x, int y )
{
return( x + y );
} /* end function sum */
/* definition of subtract */
int subtract( int x, int y )
{
return( x - y );
} /* end function subtract */
/* defintion of mult */
int mult( int x, int y )
{
return( x * y );
} /* end function mult */
/* definition of divide */
float divide( int x, int y)
{
float q; /* quotient variable */
q = ( float ) x / y;
return( q );
} /* end function divide */
/* definition of power */
int po( int x, int y )
{
int ret_value = 1;
int i; /* counter variable */
for ( i = 1; i <= y; i++ ){
ret_value *= x;
}
return( ret_value ); /* returns value at the end of the loop */
} /* end function power */
/* definition of gcd */
int gcd( int x, int y )
{
int r;
if ( x > y ) {
while ( y != 0 ){
r = x % y;
x = y;
y = r;
return( x );
}
else if ( y > x ) {
while ( x != 0 ){
r = y % x;
y = x;
x = r;
}
return ( y );
}
} /* end fuction gcd */
/* definition of factorial */
int fact( int x )
{
int f = 1;
int c;
for (c = x; c >= 1; c-- ) {
f *= c;
}
return( f );
} /* end function factorial */
I get the following compile errors:
