C program to generate electricity bill

Below is the program to generate electricity bill

#include <stdio.h>
int main(){
    char name[20];
    int units,mincharge=100;
    double s1=0.80,s2=0.90,s3=1.00,surcharge=0.15,billamt=0.0;
    printf("Enter the name of consumer:\n");
    scanf("%s",&name);
    printf("Enter the number of units consumed:\n");
    scanf("%d",&units);
    billamt=billamt+mincharge;
    if(units<=200){
        billamt=billamt+(units*s1);
    }
    else if(units >200 && units<=300){
        billamt=billamt+((200*s1)+(units-200)*s2);
    }
    else{
        billamt=billamt+(200*s1)+(100*s2)+((units-300)*s3);
    }
    if(billamt>400){
        billamt=billamt+(billamt*surcharge);
    }
    printf("Consumer name=%s\n",name);
    printf("Units consumed =%d\n",units);
    printf("Billamount=%f rupees\n",billamt);
}

Output:

Enter the name of consumer:
vinny
Enter the number of units consumed:
600
Consumer name=vinny
Units consumed =600
Billamount=747.500000 rupees