问题
I have a program in class that reads a data file for a store and then prints them out on a prompt.
1 Suits 300 100 92
1 Coats 200 60 65
1 Shirts 1000 12 13
2 Dresses 400 60 65
2 Coats 185 184 200
2 Shoes 600 40 30
3 Jeans 200 40 35
3 Shoes 200 30 34
4 Jeans 300 42 43
The numbers being department, item name, quantity, cost to buy, and cost to sale.
#include <stdio.h>
#include <stdlib.h>
#ifndef min
#define min(a,b) ((a) < (b) ? (a) : (b))
#endif
int main()
{
FILE *in;
char item[8];
int department, quantity, prev = 1,k=0;
float cost, market, cost2, mark2, total, totcost, totmark = 0, lowest;
if((in = fopen("blinn.dat", "r")) == NULL)
{
printf ("Can't open file blinn.dat\n");
system("pause");
exit(1);
}
else
{
printf ("\n\n\t\t\t\t Blinn Apparel Store");
printf ("\n\n\n\t\t Unit Cost Extended");
printf ("\n Quantity Cost Market Cost Market Lower Cost\n");
printf ("\nMens Dept");
int m=0;
while(fscanf(in, "%d %s %d %f %f", &department, item, &quantity, &cost, &market) != EOF)
{
if(department != prev)
{
lowest = min(totcost, totmark);
printf ("\n Total\t\t\t\t $%8.2f $%8.2f $%8.2f", totcost, totmark, lowest);
totcost = 0;
totmark = 0;
prev = department;
total += lowest;
switch (m)
{
case 0:
printf("\nLadies Dept");
break;
case 1:
printf("\nGirls Dept");
break;
case 2:
printf("\nBoys Dept");
break;
}
m++;
}
if (department == 1)
{
cost2 = cost * quantity;
mark2 = market * quantity;
printf ("\n%8s %4d %8.2f %4.2f %8.2f %8.2f ",
item, quantity, cost, market, cost2, mark2);
totcost = totcost + cost2;
totmark = totmark + mark2;
}
if (department == 2)
{
cost2 = cost * quantity;
mark2 = market * quantity;
printf ("\n%8s %4d %8.2f%8.2f %8.2f %8.2f ",
item, quantity, cost, market, cost2, mark2);
totcost = totcost + cost2;
totmark = totmark + mark2;
}
if (department == 3)
{
cost2 = cost * quantity;
mark2 = market * quantity;
printf ("\n%8s %4d %8.2f %5.2f %8.2f %8.2f ",
item, quantity, cost, market, cost2, mark2);
totcost = totcost + cost2;
totmark = totmark + mark2;
}
if (department == 4)
{
cost2 = cost * quantity;
mark2 = market * quantity;
printf ("\n%8s %4d %8.2f %5.2f %8.2f %8.2f ",
item, quantity, cost, market, cost2, mark2);
totcost = totcost + cost2;
totmark = totmark + mark2;
lowest = min(totcost, totmark);
printf ("\nTotal\t\t\t\t\t $%8.2f $%8.2f $%8.2f\n", totcost, totmark, lowest);
total += lowest;
}
}
}
printf("Inventory at lower cost\t\t\t\t\t $%8.2f\n", total);
system ("pause");
}a
Disregard the nonuniform spacing for each line; I was troubleshooting a large number I was inexplicably getting. I have the code done all nice and dandy and it all checks out, but my professor has given me half credit because of the if statements, saying if there were a large number of departments my code wouldn't be feasible. He said I could replace it with one statement and that threw me off because I've tried working it into the switch statement, but that obviously doesn't work because some of the clothing items don't appear.
I just can't seem to change things without the math going crazy. My first thought was to make a function for the multiple additions and multiplications to totmark, totcost, cost2, and mark2, but anytime I disrupt it, everything falls apart and I can't seem to put it back together.
This should be an easy fix, but I appreciate any help.
回答1:
I think they expect you to make use of function.
You could also use Structures.
/* Structure Definition */
typedef struct goods
{
int dept;
char item[64];
int quantity;
int sell_price;
int cost_price;
} goods_t;
and create an array of structures (in main()), like this
/* Array of Structure */
#define NO_ENTRIES 10 /* No of entries in your file */
goods_t arr[NO_ENTRIES];
for(i = 0; i< TOTAL_DEPT; i++)
{
fscanf(fp, "%d %s %d %d %d", &arr[i].dept, arr[i].item, &arr[i].quantity, &arr[i].sell_price, &arr[i].cost_price);
cal(arr[i].dept, arr[i].item, arr[i].quantity, arr[i].sell_price ,arr[i].cost_price);
}
Also you could write a generic function to calculate:
void calculate (int dept, char *item, int quantity, int sp, int cp)
{
int total_cost = 0, total_market = 0;
total_cost += quantity * cp;
total_sell += quantity * sp;
...
printf("%s\t%d\t%d\t%d\n", item, quantity, sp, cp);
printf("Total : %d\t %d\n", total_cost, total_sell);
...
return;
}
Side Note:
You could use enum
enum type{
mens = 0,
ladies,
boys,
girls,
};
and add the following to function calculate
if(dept == mens)
printf("Mens Dept");
else if(dept == ladies)
printf("Ladies Dept");
else if(dept == boys)
printf("Boys Dept");
else
printf("Girls Dept");
回答2:
perhaps you could try using arrays like;
int department[ k]
string itemname[ ]
Float quantity[ ] , cost_to_buy[ ],
cost_to_sale[ ]
Ask the user for k number of departments if necessary for feasibility After this you can apply a switch or if statement to assign each array its equivalent and then display using a for-loop for each. With arrays you can work with larger number of departments Good luck
回答3:
the following compiles with no warnings/errors
it implements the logic needed
however, certain printf statements and certain calcuations
are left for the OP
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
static const char * departmentNames[] =
{
"Mens Department",
"Womens Department",
"Girls Department",
"Boys Department"
};
int main()
{
int firstRecord = 1;
FILE *in;
char item[20];
int departmentNum = 0;
int quantity = 0;
int prevDepartmentNum = 0;
float cost = 0.0f; // store cost of one item
float market = 0.0f; // customer cost of one item
float cost2 = 0.0f; // cost * quantity
float mark2 = 0.0f; // narket * quantity
float totcost = 0.0f; // sum of product cost for one department
float totmark = 0.0f; // sum of product sales for one department
if((in = fopen("blinn.dat", "r")) == NULL)
{
perror( "fopen for reading blinn.data failed" );
printf ("Can't open file blinn.dat\n");
system("pause");
exit( EXIT_FAILURE );
}
// implied else, fopen successful
// display the report header
printf ("\n\n\t\t\t\t Blinn Apparel Store");
printf ("\n\n\n\t\t Unit Cost Extended");
printf ("\n Quantity Cost Market Cost Market\n");
while(1)
{
memset(item, 0x00, sizeof(item) );
if( 5 != fscanf(in, " %d %19s %d %f %f", &departmentNum, item, &quantity, &cost, &market) )
{ // fscanf failed
perror( "fscanf failed" );
exit( EXIT_FAILURE );
}
// implied else, fscanf successful
if( firstRecord )
{
firstRecord = 0;
prevDepartmentNum = departmentNum;
totcost = 0.0f;
totmark = 0.0f;
} // end if
if(departmentNum != prevDepartmentNum)
{ // then output previous department totals
printf( "\n%s", departmentNames[prevDepartmentNum]);
printf ("\n Total\t\t\t\t $%8.2f $%8.2f", totcost, totmark );
// re-initialize for new department
totcost = 0.0f;
totmark = 0.0f;
prevDepartmentNum = departmentNum; // prep for next itteration
} // end if
cost2 = cost * quantity;
mark2 = market * quantity;
printf ("\n%8s %4d %8.2f %4.2f %8.2f %8.2f ",
item, quantity, cost, market, cost2, mark2);
totcost = totcost + cost2;
totmark = totmark + mark2;
} // end while
system ("pause");
return(0);
} // end function: main
来源：https://stackoverflow.com/questions/27395696/reading-and-displaying-data-files-correct-results-but-code-is-unfeasible