Code:
#include <stdio.h>
int main(void)
{
int currentprice,upcomingprice;
int currentprice1,currentprice2,currentprice3;
int upcomingprice1,upcomingprice2,upcomingprice3;
int difference;
float gallons;
printf( "Enter the water consumption \n ", gallons );
	scanf( "%f", &gallons);

switch(currentprice){
      case 1:
      currentprice1=gallons*7;
...