C program for electricity bill

#include<iostream>
using namespace std;
#define cost1 0.60
#define cost2 0.80
#define cost3 0.90
#define min 50
#include<conio.h>
void main()
{
char name[10][20];
float amount[10];
int units[10],n;

cout<<"Enter Number of Customers: ";
cin>>n;

cout<<"Enter Names and Number of Units Consumed\n";
for(int i=0;i<n;i++)
{
cout<<"-------------------------\n";
cout<<"Enter Customer Name: ";
cin>>name[i];
cout<<"Enter Number of units= ";
cin>>units[i];
cout<<"-------------------------\n";

if(units[i]<=100)
{
amount[i]=(units[i]*cost1)+min;
}
else if(units[i]>100&&units[i]<=300)
{
amount[i]=(((units[i]-100)*(cost2))+(100*cost1))+min;

}
else if(units[i]>300)
{
amount[i]=(((units[i]-300)*(cost3))+(200*cost2)+(100*cost1))+min;
amount[i]=amount[i]+(amount[i]*(15.0/100.0));
}
}

cout<<"**************BILL**************\n";
cout<<"Name\t\t"<<"Units\t\t"<<"Amount\n";
for(int i=0;i<n;i++)
{
cout<<name[i]<<"\t\t"<<units[i]<<"\t\t"<<"Rs."<<amount[i];
cout<<"\n";
}
getch();
}

C program to implement Newton Raphson method

C program to implement Newton Raphson method

1)F(x)=x^2-3x+2

#include<stdio.h>

#include<math.h>

#include<conio.h>

#define e 0.001

#define F(x) (2*x)-3

float frac(float a)

{

       float f1;

       f1=a*a-3*a+2;

       return f1;

}

int main()

{

       float x1,x2,f1=0,f2,er,d;

       printf("F(x) = x^2-3x+2\n\n");

       printf("Enter the value of x1: ");

       scanf("%f",&x1);

       printf("\nx1 = %f",x1);

       printf("\n________________________________________________________________________________\n");

        

       printf("     x1      |       x2      |      f1       |       f'1      |  |(x2-x1)/x2|  |  \n");

       printf("--------------------------------------------------------------------------------\n");

       do

       {

              f1=frac(x1);

              d=F(x1);

              x2=x1-(f1/d);

              er=fabs((x2-x1)/x2);

           printf("  %f   |    %f   |     %f  |     %f  |      %f  |   \n",x1,x2,f1,d,er);

              x1=x2;

       }

       while(er>e);

       printf("--------------------------------------------------------------------------------\n\n");

       printf("\n  Root of the equation is: %f",x2);

       getch();

}