How to do this assignment in C? Part 2 - c

Question

The following prompts input for the radius and height, and uses those values to calculate the volume of a cylinder. How can I write this program so that it doesn't terminate when the user inputs a negative value for either radius of height? The range has to be 1-10 inclusive and no other prompts are allowed. The loop must be terminated only when something non-numeric is entered.
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
float areaCirc(float r){
return (M_PI*r*r);
}
float volCyl(float r, float h){
return (areaCirc(r)*h);
}
int main(void) {
float r, h;
int k = 0;
float volume;
float avgh = 0;
float toth = 0;
do{
float exit = scanf("%f%f", &r, &h);
if (exit == 0)
{break;}
if(r<=0 || r>10){
printf("Invalid radius: %.2f\n",r);
}
if(h<=0 || h>10){
printf("Invalid height: %.2f\n",h);
}
if(r>=0 && r<=10 && h>=0 && h <= 10){
volume = volCyl(r,h);
k = k++;
printf(" Cylinder %d radius %.2f height %.2f volume %.2f\n",k,r,h,volume);
toth = toth + h;
} }while(r>0 && h>0);
avgh = toth/k;
printf("Total Height: %.2f\n",toth);
printf("Average Height: %.2f\n",avgh);
return EXIT_SUCCESS;
}

Answer 1

Look at the statement inside your while(). Note that this will keep looping if and only if those conditions result in true.

Answer 2

do {
printf("Enter radius: ")
scanf("%d", &r);
printf("Enter height: ")
scanf("%d", &h);
} while(r<=0 || h<=0);
You can use a do-while loop that would keep prompting for the user to re-enter the radius and height is either value is less than or equals to 0.
Hope this helps :)

Answer 3

My specified range has to be 1 to 10 inclusive, without the negative values terminating the program, and no other prompts are allowed
Modify your main function
do{
int ex = scanf("%f%f", &r, &h); //scanf returns int
if (ex == 0)
{break;}
if(r<=0 || r>10){
printf("Invalid radius: %.2f\n",r);
continue;
}
if(h<=0 || h>10){
printf("Invalid height: %.2f\n",h);
continue;
}
// hence above conditions failed means you have given desired input
// need not to check any conditions
volume = volCyl(r,h);
k = k++;
printf(" Cylinder %d radius %.2f height %.2f volume %.2f\n",k,r,h,volume);
toth = toth + h;
}while(r>0 && h>0);
if(k>0) // check this other wise divide by zero will occur
{
avgh = toth/k;
printf("Total Height: %.2f\n",toth);
printf("Average Height: %.2f\n",avgh);
}