#include <stdio.h>
#include <stdlib.h>

int main()
{
    int selection;
    bool a=20;
    float R1,R2,R3,V,VR1,VR2,VR3,E,Rtotal,current_I,IR1;

    printf("******************************************\n");
    printf("Enter the value of R1= \n");
    scanf("%f", &R1);
    printf("Enter the value of R2= \n");
    scanf("%f", &R2);
    printf("Enter the value of R3= \n");
    scanf("%f", &R3);
    printf("Enter the value of E= \n");
    scanf("%f", &E);
    printf("******************************************\n");
    printf("1. Total resistance of the circuit, Rtotal \n");
    printf("2. Current, I \n");
    printf("3. Voltage drop across resistor 8ohm, VR3 \n");
    printf("4. Current through resistor 4ohm, IR1 \n");
    printf("Please Select your choice \n");
    printf("******************************************\n");
    scanf("%d",&selection);

	Rtotal = (1/(1/R1 +1/R2+1/R3)) ;
	current_I = (20/Rtotal);
	VR3 = E ;
	IR1 = (20/R1);

    if (selection==1)
    {
    printf("Total resistance = %.6f ohm\n", Rtotal);
    }
    else if (selection==2)
    {
        printf("Current_I = %.3f A\n", current_I);
    }
    else if (selection==3)
    {
        printf("VR3 = %f \n", VR3);
    }
    else if (selection==4)
    {
        printf("IR1 = %f \n", IR1);
    }
    else
    {
        printf("wrong choice \n");
    }
    return 0;
}