zan_nabil

// Jubayer Al Nazi
// Code with comments (documentation)

// include statements, header files
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>


//constants
#define SIZ 1000  // maximum size of stack

int stack_len; // this variable contains the current
//length of the stack, so if it's 0 means stack is empty
//I have used 1 based indexing, meaning in my stack
//stack[0] is empty, there's nothing
//useful screwdriver price is kept from index 1
//stack[1] <- price of screwdriver 1

struct data{

float cost; // this struct object contains the cost of sd

};
struct data stack[SIZ+1]; // stack to contain prices of
//individual screwdriver, maximum 1000 screwdrivers


char command[100]; // a string, each time the command query will be saved
// in here, input by the sales manager
int max(int a, int b)
{
    if(a>=b)
        return a;
    return b;


}
void PUSH(float price) // take a price and
{
    // add it to the stack from behind
    stack_len++; // a new item added to stack, so increase length by 1
    stack[stack_len].cost = price; // keep the price in stack

}
float POP()
{
    double ret = stack[stack_len].cost; //return the last
    //element of stack
    stack_len--; // decrease the stack size by 1
    // so the last element is deleted now
    return ret;

}



// Main program
int main()
{


    //global variables are initialized as 0, so
    //stack_len = 0, initially, meaning empty stack

    int exit_prog = 0; // when it's true, we
    //will exit
    printf("Start of Program\n");
    for(;exit_prog==0;)
    {
        printf("\n\nSALE Format: s NUMBER_OF_SCREWDRIVER\n");
        printf("Receipt format: r NUMBER_OF_SCREWDRIVER PRICE_OF_EACH_ITEM\n");
        printf("Exit format: e\n\n\n");

        scanf("%s",command); // take input from console

        if(strcmp(command,"e")==0) // if input is equal to 'e'
        {
            exit_prog = 1;
            //time to exit
        }
        else if(command[0]=='s' // sale report input
                || command[0]=='S')
        {
            float total_prc = 0.0;

            int num_sd = 0; //number of screwdrivers
            scanf("%d",&num_sd);
            float last_c; // last cost to check if two types of items are
            // sold, to update the sale counter properly

            stack_len = max(stack_len,0);
            //stack size can't be negative

            if(stack_len!=0) // not empty
            {
                last_c = stack[stack_len].cost;
                //new type of item discovered
            }
            else
            {
                //stack is empty
                printf("NOT AVAILABLE FOR SALE!\n");

            }

            //enough screwdrivers for sale
            //first price is saved in last_c
            //so, lets delete it, as already sold
            int sold = 1;
            POP(); //1 item sold, delete it from stack

            int num_prc = 1; // number of screwdriver of same cost



            while(sold<num_sd) //stack is not empty
                // and sold items < number of screwdriver --> means
                // we can sell more
            {
                if(stack_len<=0)
                    break;
                float cost = stack[stack_len].cost;
                if(cost!=last_c) // if both current cost
                    // and last seen costs are not same, that means we are
                    //dealing with different screwdrivers now of different cost
                {
                    // so, print the updated sales
                    printf("%d SCREWDRIVERS SOLD AT RM %f\n",num_prc,last_c);
                    total_prc += num_prc*last_c;
                    sold++;
                    POP();
                    last_c = cost;

                    num_prc = 1; // done updating
                }
                else
                {
                    sold++; // 1 more sold
                    POP(); //delete it from stack
                    num_prc++; // same price

                }



            }

            stack_len = max(stack_len,0);
            total_prc += num_prc*last_c;
            if(fabs(total_prc)>0.001) // if only we sold more than 0 RM, then print
            {
                printf("%d SCREWDRIVERS SOLD AT RM %f\n\n",num_prc,last_c);


                printf("SALE -> %f\n", total_prc);
            }
        }

        else if(command[0]=='r'
                || command[0]=='R') //input receipt
        {


            float sd_price = 0; //number of screwdrivers

            int num_sd = 0; //number of screwdrivers

            scanf("%d %f",&num_sd,&sd_price);

            for(int sd_now=1; sd_now<=num_sd; sd_now++)
            {
                PUSH(sd_price);
            }

            printf("Receipt Received %d items at %f RM per item\n",num_sd,sd_price);


            printf("SD in stock now : %d\n",stack_len);

        }



    }



    return 0;
}