usaa20/cv2/program.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define LINE_LEN 100
#define LIST_SIZE 128
typedef struct {
    char name[LINE_LEN];
    float price;
} pizza;
int get_line(char *name);
int get_pizza(pizza *p_item);
int compare_pizza(const void* pVoid1, const void* pVoid2);
int main() {
    pizza items[LIST_SIZE];
    memset(items,0,sizeof(items));
    int count = 0;
    while(get_pizza(items + count)) {
        count++;
    }
    qsort(items, count, sizeof(pizza), compare_pizza);
    int i = 0;
    while(i < count) {
        printf("%s\n%f\n", items[i].name, items[i].price);
        i++;
    }
    return 0;
}
int get_line(char *name)
{
    memset(name, 0, LINE_LEN);
    char* r = fgets(name, LINE_LEN, stdin);
    if (r == NULL || name[1] == 0) {
        return 0;
    }
    int n = strlen(name);
    if (name[n - 1] == '\n')
        name[n - 1] = 0;
    return 1;
}
int get_pizza(pizza *p_item)
{
    int res = get_line(p_item->name);
    char price_string[LINE_LEN];
    res += get_line(price_string);
    if (res != 2) return 0;
    sscanf(price_string, "%f", &(p_item->price));
    if(p_item->price == 0.) return 0;
    return 1;
}
int compare_pizza(const void* pVoid1, const void* pVoid2) {
    pizza* pPizza1 = (pizza*) pVoid1;
    float price1 = pPizza1->price;
    pizza* pPizza2 = (pizza*) pVoid2;
    float price2 = pPizza2->price;
    float r = price1 - price2;
    if (r > 0.) return 1;
    if (r < 0.) return -1;
    char* name1 = pPizza1->name;
    char* name2 = pPizza2->name;
    if (r == 0.) return strcmp(name1,name2);
}