Thread: C program for serial and parallel resistors

Hello,

I'm working on a program to calculate the total resistor of a network of resistors. In this program I have to ask the user how many resistors are serial and how many are parallel. Until that part it goes quite well, but I'm having trouble with the part where I connect the answer of the user to how often the program goes through my loop.

I tried to make it work with a for and a while loop but I can't figure it out.

Code:

//Programma voor het berekenen van de vervangingsweerstand van een laddernetwerk van weerstanden.#include <stdio.h>
#include <math.h>


float Rvserial;
float Rvparallel;
float Rs, Rp;
float totalserial, totalparallel;




void main(void)
{
    printf("In this program will calculate the total resistor of your network\n");
    printf("How many serialresistors do you have?\t");
    scanf("%f", &totalserial);
    printf("How many prallelresistors do you have?\t");
    scanf("%f", &totalparallel);


    while (Rs >= 0) {
        printf("Enter your values of the serial resistors. Negative value is stop\n");
        printf("Give the value in ohms\t\t");
        scanf("%f", &Rs);
        if (Rs >= 0) {
            Rvserial = Rvserial + Rs;
        }
    }
    printf("Enter your values of the parallel resistors. Negativ value is stop.\n");
    printf("Give the value in ohms \t\t");
    scanf("%f", &Rp);
    if (Rp >= 0){
        Rvparallel =

This is what I have for now. As you can see it is far from finished and I have certain things with no use in combination with other lines, but that is just my mind at the moment.

I hope someone can give me a clear vision.

Don't use void main().

Yes okay I know my code is off, so forget my incorret code for a moment. I want that the program gets a number from the user, this is how many serial resistors there are. If for instance that number were 4, then I want the program to ask 4 times for a value of the resistor. That single thing could be solved with an if-statement. BUT, I also want that the program gets a number from the user which refers to how many parallel resistors there are. And then it should ask how many parallel resistors there are, according to that number. And then I feel like an if-statement won't work anymore, because you have two 'unknows'.

while is just a looping if statement. I don't know anything about resistors, but if you need to loop as many times as the user dictates, you can just use the user entry as your condition and decrement it ever iteration.

Code:

int times = 0;
puts("Loop how many times?");
scanf("%d", &times);
while (times > 0) {
    // do something
    times = times - 1; // or --times;
}

If you are saying that you need to have variables for the user to enter data into, you could make an array to hold that data.

Code:

void condition() {
	int arr[100] = { 0 };
 
	int times = 0;
	puts("Loop how many times?");
	scanf("%d", &times);
	while (times > 0) {
		puts("Enter a number.");
		scanf("%d", arr[times]);
		--times;
	}
}

Thankyou jack, I think this is what I've been looking for. For now this helps me a lot! If I have more questions, I'll come back.