station

cv6/a_station.c

@@ -0,0 +1,94 @@
+#include "a_station.h"
+#include <stdlib.h>
+#include <string.h>
+
+struct station* create_station(){
+   struct station* station = (struct station*)calloc(1,sizeof(struct station));
+   station->tracks = (struct car**)calloc(STATION_SIZE, sizeof(struct car*));
+   station->track_count = STATION_SIZE;
+   return station;
+}
+
+void destroy_station(struct station* station){
+    for(int i = 0; i < station->track_count; i++){
+        struct car* this = station->tracks[i];
+        while(this != NULL){
+            struct car* delete = this;
+            this = delete->next;
+            free(delete);
+        }
+    }
+    free(station->tracks);
+    free(station);
+
+}
+
+int select_track(struct station* station, const char* target){
+    unsigned int hash = 0;
+    for(int i = 0; target[i] != '\0'; i++){
+        hash = target[i] + (hash << 6) + (hash << 16) - hash;
+    }
+    if(hash < 0 || hash > station->track_count){
+        hash = hash % station->track_count;
+    }
+    return hash;
+}
+
+void add_target_capacity(struct station* station,const char* target, int capacity){
+    int track = select_track(station, target);
+    struct car* start = station->tracks[track];
+    while(start != NULL){
+        int x = strcmp(start->value, target);
+        if(x == 0){
+            start->capacity = start->capacity + capacity;
+            return;
+        }
+        start = start->next;
+    }
+    struct car* newcar = calloc(1, sizeof(struct car));
+    strcpy(newcar->value, target);
+    newcar->capacity = capacity;
+    newcar->next = start;
+    station->tracks[track] = newcar;
+    if(newcar->next){
+        return;
+    }
+    return;   
+
+}
+
+int get_target_capacity(struct station* station,const char* target){
+    int track = select_track(station, target);
+    struct car* start = station->tracks[track];
+    while(start != NULL){
+        int x = strcmp(start->value, target);
+        if(x == 0){
+            return start->capacity;
+        }
+        start = start->next;
+    }      
+    return 0;
+}
+
+int count_targets(struct station* station){
+    int targets = 0;
+    for(int i = 0; i < STATION_SIZE; i++){
+        if(station->tracks[i] != NULL){
+            targets++;
+        }
+    }
+    return targets;
+}
+
+int count_capacity(struct station* station){
+    int capacity = 0;
+    for(int i = 0; i < STATION_SIZE; i++){
+        struct car* this = station->tracks[i];
+        if(this != NULL){
+            capacity = capacity + this->capacity;
+            this = this->next;
+        }       
+    }
+    return capacity;
+}
+

cv6/a_station.h

@@ -0,0 +1,91 @@
+#ifndef STATION_H
+#define STATION_H
+// Pocet trati k dispozicii
+#define STATION_SIZE 10
+// Maximalny pocet znakov pre ulozenie nazvu cielovej stanice
+#define TARGET_SIZE 36
+
+/**
+ * Jeden zaznam o kapacite do cielovej stanice
+ */
+struct car {
+    // Cielova stanica / nazov
+    char value[TARGET_SIZE];
+    // Pocet cestujuchich
+    int capacity;
+    // Smernik na dalsi zaznam
+    struct car* next;
+};
+
+/**
+ * Cela databaza zaznamov
+ */
+struct station {
+    // Dynamicke pole smernikov na zaznamy
+    // jeden zaznam ma typ struct car*
+    struct car** tracks;
+    // Velkost pola tracks
+    int track_count;
+};
+
+
+/**
+ * Vytvori prazdnu stanicu.
+ * Alokuje pole smernikov tracks na pociatocnu kapacitu STATION_SIZE
+ * nastavi velkost capacity na STATION_SIZE
+ * @return smernik na prazdnu stanicu
+ */
+struct station* create_station();
+
+/**
+ * Uvolni pamat
+ * @param smernik na databazu
+ */
+void destroy_station(struct station* station);
+
+/**
+ * Vyberie poziciu v poli station->tracks pre ulozenie zaznamu target
+ *
+ * Proces vyberu by mal splnat kriteria pre hash funkciu:
+ * - rovnaky retazec by mal vzdy mat rovnaky vysledok
+ * - pre rozne retazce by mali byt vysledky co najviac rozne
+ *
+ * @param smernik na databazu
+ * @param nazov cielovej stanice
+ * @return cislo v intervale 0 az N-1, kde N je  station->track_count
+ */
+int select_track(struct station* station, const char* target);
+
+/**
+ * Zvysi zaznam o pocte cestujucich do danej cielovej stanice.
+ *
+ * Najprv sa vyberie cielova trat pomocou select_track(). Ak zaznam neexistuje, 
+ * vytvori sa novy. Ak zaznam na danej trati (spojkovom zozname) existuje, cislo sa pripocita.
+ * V databaze nesmu byt dva zaznamy s rovnakou cielovou stanicou.
+ *
+ * @param smernik na databazu
+ * @param nazov cielovej stanice
+ */
+void add_target_capacity(struct station* station,const char* target, int capacity);
+
+/**
+ * Ziska zaznam o cielovej stanici.
+ * @param smernik na databazu
+ * @param nazov cielovej stanice
+ *
+ * @return kapacitu do cielovej stanice. Ak sa zaznam nenachedza, vrati nula.
+ */
+int get_target_capacity(struct station* station,const char* target);
+
+/**
+ * Spocita pocet cielovych stanic
+ * @param smernik na databazu
+ */
+int count_targets(struct station* station);
+
+/**
+ * Spocita kapacitu vo vsetkych zaznamoch
+ * @param smernik na databazu
+ */
+int count_capacity(struct station* station);
+#endif