funguje

du2/program.c

@@ -0,0 +1,111 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#define LINE_SIZE 100
+#define LIST_SIZE 100
+
+struct pizza
+{
+    char name[LINE_SIZE];
+    float prize;
+};
+
+int read_item(struct pizza *item) 
+{
+    char name_buffer[100];
+    char price_buffer[20];
+    if (fgets(name_buffer, sizeof(name_buffer), stdin) == NULL) 
+    {
+        return 0;
+    }
+    size_t len = strlen(name_buffer);
+    if (len > 0 && name_buffer[len-1] == '\n') 
+    {
+        name_buffer[len-1] = '\0';
+    }
+    if (strlen(name_buffer)==0) 
+    {
+        return 0;
+    }
+    if (fgets(price_buffer, sizeof(price_buffer), stdin)==NULL) 
+    {
+        return 0;
+    }
+    float prize;
+    if (sscanf(price_buffer, "%f", &prize)!=1) 
+    {
+        return 0;
+    }
+    if (prize<=0) 
+    {
+        return 0;
+    }
+    strcpy(item->name, name_buffer);
+    item->prize=prize;
+    return 1; 
+}
+
+int read_pizza_list(struct pizza* list)
+{
+    int counter=0;
+    for (int i=0; i< LIST_SIZE; i++)
+    {
+        struct pizza item;
+        memset(&item,0,sizeof(struct pizza));
+        int r=read_item(&item);
+        if (r)
+        {
+            memcpy(&list[i],&item,sizeof(struct pizza));
+            counter+=1;
+        }
+        else
+        {
+            break;
+        }
+    }
+    return counter;
+}
+
+int compare (const void * a, const void * b)
+{
+    const struct pizza* pizza_a=a;
+    const float prize_a=pizza_a->prize;
+    const char* name_a=pizza_a->name;
+    const struct pizza* pizza_b=b;
+    const float prize_b=pizza_b->prize;
+    const char* name_b=pizza_b->name;
+    float r=prize_a-prize_b;
+    if (r>0)
+    {
+        return 1;
+    }
+    else if (r<0)
+    {
+        return -1;
+    }
+    else
+    {
+        int r2=strcmp(name_a,name_b);
+        if (r2>0)
+        {
+            return 1;
+        }
+        else if (r2<0)
+        {
+            return 1;
+        }
+    }
+    return 0;
+}
+
+int main ()
+{
+    struct pizza list[LIST_SIZE];
+    memset(list,0,LIST_SIZE*sizeof(struct pizza));
+    int count=read_pizza_list(list);
+    qsort(list, count, sizeof(struct pizza), compare);
+    for (size_t i = 0; i < count; i++)
+    {
+        printf("%s %f\n", list[i].name, list[i].prize);
+    }    
+}