105 lines
2.9 KiB
C
105 lines
2.9 KiB
C
#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;
|
|
}
|
|
|
|
|
|
/* djb2 hash function by Dan Bernstein - deterministic and simple */
|
|
static unsigned long hash_str(const char *str) {
|
|
unsigned long hash = 5381;
|
|
int c;
|
|
while ((c = (unsigned char)*str++))
|
|
hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
|
|
return hash;
|
|
}
|
|
|
|
void destroy_station(struct station* station){
|
|
if(!station) return;
|
|
if(station->tracks){
|
|
for(int i = 0; i < station->track_count; ++i){
|
|
struct car* cur = station->tracks[i];
|
|
while(cur){
|
|
struct car* next = cur->next;
|
|
free(cur);
|
|
cur = next;
|
|
}
|
|
}
|
|
free(station->tracks);
|
|
}
|
|
free(station);
|
|
}
|
|
|
|
int select_track(struct station* station, const char* target){
|
|
if(!station || !target) return 0;
|
|
unsigned long h = hash_str(target);
|
|
return (int)(h % (unsigned long)station->track_count);
|
|
}
|
|
|
|
void add_target_capacity(struct station* station,const char* target, int capacity){
|
|
if(!station || !target || capacity == 0) return;
|
|
int idx = select_track(station, target);
|
|
struct car* cur = station->tracks[idx];
|
|
struct car* prev = NULL;
|
|
while(cur){
|
|
if(strncmp(cur->value, target, TARGET_SIZE) == 0){
|
|
cur->capacity += capacity;
|
|
return;
|
|
}
|
|
prev = cur;
|
|
cur = cur->next;
|
|
}
|
|
/* not found -> create new record and append at head for simplicity */
|
|
struct car* node = (struct car*)calloc(1, sizeof(struct car));
|
|
if(!node) return; /* allocation failed */
|
|
strncpy(node->value, target, TARGET_SIZE - 1);
|
|
node->value[TARGET_SIZE-1] = '\0';
|
|
node->capacity = capacity;
|
|
node->next = station->tracks[idx];
|
|
station->tracks[idx] = node;
|
|
}
|
|
|
|
int get_target_capacity(struct station* station,const char* target){
|
|
if(!station || !target) return 0;
|
|
int idx = select_track(station, target);
|
|
struct car* cur = station->tracks[idx];
|
|
while(cur){
|
|
if(strncmp(cur->value, target, TARGET_SIZE) == 0){
|
|
return cur->capacity;
|
|
}
|
|
cur = cur->next;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int count_targets(struct station* station){
|
|
if(!station) return 0;
|
|
int count = 0;
|
|
for(int i = 0; i < station->track_count; ++i){
|
|
struct car* cur = station->tracks[i];
|
|
while(cur){
|
|
count++;
|
|
cur = cur->next;
|
|
}
|
|
}
|
|
return count;
|
|
}
|
|
|
|
int count_capacity(struct station* station){
|
|
if(!station) return 0;
|
|
int total = 0;
|
|
for(int i = 0; i < station->track_count; ++i){
|
|
struct car* cur = station->tracks[i];
|
|
while(cur){
|
|
total += cur->capacity;
|
|
cur = cur->next;
|
|
}
|
|
}
|
|
return total;
|
|
}
|