清空array 的問題！（C 語言） - JBTALKS.CC

#include <stdio.h>
#include "readline.h"
#define NAME_LEN 25
#define MAX_PARTS 100
struct part {
int number;
char name[NAME_LEN+1];
int on_hand;
} inventory[MAX_PARTS];
int num_parts = 0; /* number of parts currently stored */
int find_part(int number);
void insert(void);
void search(void);
void update(void);
void delete1(void);
void print(void);
/**********************************************************
* main: Prompts the user to enter an operation code, *
* then calls a function to perform the requested *
* action. Repeats until the user enters the *
* command 'q'. Prints an error message if the user *
* enters an illegal code. *
**********************************************************/
int main(void)
{
char code;
for (;;) {
printf("Enter operation code: ");
scanf(" %c", &code);
while (getchar() != '\n') /* skips to end of line */
;
switch (code) {
case 'i': insert();
break;
case 's': search();
break;
case 'u': update();
break;
case 'p': print();
break;
case 'd': delete();
break;
case 'q': return 0;
default: printf("Illegal code\n");
}
printf("\n");
}
}
/**********************************************************
* find_part: Looks up a part number in the inventory *
* array. Returns the array index if the part *
* number is found; otherwise, returns -1. *
**********************************************************/
int find_part(int number)
{
int i;
for (i = 0; i < num_parts; i++)
if (inventory[i].number == number)
return i;
return -1;
}
/**********************************************************
* insert: Prompts the user for information about a new *
* part and then inserts the part into the *
* database. Prints an error message and returns *
* prematurely if the part already exists or the *
* database is full. *
**********************************************************/
void insert(void)
{
int part_number;
if (num_parts == MAX_PARTS) {
printf("Database is full; can't add more parts.\n");
return;
}
printf("Enter part number: ");
scanf("%d", &part_number);
if (find_part(part_number) >= 0) {
printf("Part already exists.\n");
return;
}
inventory[num_parts].number = part_number;
printf("Enter part name: ");
read_line(inventory[num_parts].name, NAME_LEN);
printf("Enter quantity on hand: ");
scanf("%d", &inventory[num_parts].on_hand);
num_parts++;
}
/**********************************************************
* search: Prompts the user to enter a part number, then *
* looks up the part in the database. If the part *
* exists, prints the name and quantity on hand; *
* if not, prints an error message. *
**********************************************************/
void search(void)
{
int i, number;
printf("Enter part number: ");
scanf("%d", &number);
i = find_part(number);
if (i >= 0) {
printf("Part name: %s\n", inventory[i].name);
printf("Quantity on hand: %d\n", inventory[i].on_hand);
} else
printf("Part not found.\n");
}
/**********************************************************
* update: Prompts the user to enter a part number. *
* Prints an error message if the part doesn't *
* exist; otherwise, prompts the user to enter *
* change in quantity on hand and updates the *
* database. *
**********************************************************/
void update(void)
{
int i, number, change;
printf("Enter part number: ");
scanf("%d", &number);
i = find_part(number);
if (i >= 0) {
printf("Enter change in quantity on hand: ");
scanf("%d", &change);
inventory[i].on_hand += change;
} else
printf("Part not found.\n");
}
/**********************************************************
* print: Prints a listing of all parts in the database, *
* showing the part number, part name, and *
* quantity on hand. Parts are printed in the *
* order in which they were entered into the *
* database. *
**********************************************************/
void print(void)
{
int i;
printf("Part Number Part Name "
"Quantity on Hand\n");
for (i = 0; i < num_parts; i++)
printf("%7d %-25s%11d\n", inventory[i].number,inventory[i].name, inventory[i].on_hand);
}
void delete1(void)
{
int i, number, change;
printf("Enter part number: ");
scanf("%d", &number);
i = find_part(number);
if (i >= 0)
{
inventory[i].name='\0';
inventory[i].number=0;
inventory[i].on_hand=0;
num_parts--;
}
else
printf("Part not found.\n");
}

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