VoidList - file .c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct elem_t elem_t;
typedef struct list_t list_t;

struct elem_t {
    void * key;
    struct elem_t * next;
};

struct list_t{
    struct elem_t * head;
    int (*compare) (void*,void*);
    void * (*copyk) (void*);
    void (*print_list) (struct elem_t*);
};

int compare_int(void *a, void *b){
    int *a1, *b1;
    a1 = (int*) a;
    b1 = (int*) b;
    return ((*a1)-(*b1));
}

int compare_string(void *a, void *b){
    char *a1, *b1;
    a1 = (char*) a;
    b1 = (char*) b;
    return (strcmp(a1,b1));
}

void * copyk_int(void *a){
    int *a1;
    if((a1 =  (int*) malloc(sizeof(int)))==NULL)
        return NULL;
    *a1= * (int*) a;
    return (void*) a1;
}

void * copyk_string(void *a){
    char* a1;
    int len;
    if(((char*)a)==NULL)
        return NULL;
    len=strlen((char*)a);
    if((a1 =(char*) malloc((len+1)*sizeof(char)))==NULL)
        return NULL;
    strcpy(a1,(char*)a);
    return (void*) a1;
}

void print_int_list(elem_t *list){
    elem_t *iter;
    if(list == NULL)
        printf("[WARNING @ print_int_list] empty list\n");
    else{
        iter = list;
        while(iter != NULL){
            printf("%d ->",(int) iter->key);
            iter = iter->next;
        }
        printf("# end of list\n");
    }
}

void print_string_list(elem_t *list){
    elem_t *iter;
    if(list == NULL)
        printf("[WARNING @ print_string_list] empty list\n");
    else{

        iter = list;
        while(iter != NULL){
            printf("%s ->",(char*) iter->key);
            iter = iter->next;
        }
        printf("# end of list\n");
    }
}

list_t* create_int_list(){
    list_t *new_list;
    if((new_list = (list_t*) malloc(sizeof(list_t)))==NULL){
        printf("[ERROR @ create_int_list] couldn't allocate heap\n");
        return NULL;
    }
    new_list->head = NULL;
    new_list->compare = compare_int;
    new_list->copyk = copyk_int;
    new_list->print_list = print_int_list;
    return new_list;
}

list_t* create_string_list(){
    list_t *new_list;
    if((new_list = (list_t*) malloc(sizeof(list_t)))==NULL){
        printf("[ERROR @ create_int_list] couldn't allocate heap\n");
        return NULL;
    }
    new_list->head = NULL;
    new_list->compare = compare_string;
    new_list->copyk = copyk_string;
    new_list->print_list = print_string_list;
    return new_list;
}

void printList(list_t *list){
    if(list == NULL)
        printf("[WARNING @ printList] empty list\n");
    else
        list->print_list(list->head);
}

void insert_inList(list_t* list, void * new_key){
    if(list->head == NULL){
        if((list->head = (elem_t*) malloc(sizeof(elem_t)))==NULL){
            printf("[ERROR @ insert_inList] couldn't allocate memory into the heap\n");
            exit(1);
        }
        list->head->key = list->copyk(new_key);
        list->head->next = NULL;
    }
    else{
        elem_t *curr = list->head, *succ = list->head->next, *new_element;
        if((list->compare(new_key,list->head->key))<0){
            if((new_element = (elem_t*) malloc((sizeof(elem_t))))==NULL){
                printf("[ERROR @ insert_inList] couldn't allocate memory into the heap\n");
                exit(1);
            }
            new_element->key = list->copyk(new_key);
            new_element->next = curr;
            list->head = new_element;
        }
        else{
            while((succ != NULL)&&((list->compare(new_key,succ->key))>=0)){
                curr = succ;
                succ = succ->next;
            }
            if((new_element = (elem_t*) malloc((sizeof(elem_t))))==NULL){
                printf("[ERROR @ insert_inList] couldn't allocate memory into the heap\n");
                exit(1);
            }
            new_element->key = list->copyk(new_key);
            new_element->next = succ;
            curr->next = new_element;
        }
    }
}

list_t* free_list(list_t* list){
    if(list->head != NULL){
        elem_t *curr = list->head, *succ = list->head->next;
        while(curr != NULL){
            free(curr->key);
            free(curr);
            curr = succ;
            if(succ != NULL) succ = succ->next;
        }
    }
    free(list);
    return NULL;
}

void extract_fromList(list_t *list, void *x_key){
    if(list == NULL)
        printf("[WARNING @ extract_fromList] empty list\n");
    else{
        if(list->head == NULL)
            printf("[WARNING @ extract_fromList] empty list\n");
        else{
            elem_t *curr = list->head, *succ = list->head->next;
            if(!(list->compare(x_key,list->head->key))){
                list->head = succ;
                free(curr->key);
                free(curr);
            }
            else{
                while((succ != NULL)&&((list->compare(x_key,succ->key))>0)){
                    curr = succ;
                    succ = succ->next;
                }
                if(succ == NULL)
                    printf("[WARNING @ extract_fromList] element not found\n");
                else{
                    if((list->compare(x_key,succ->key))<0)
                        printf("[WARNING @ extract_fromList] element not found\n");
                    else{
                        curr->next = succ->next;
                        free(succ->key);
                        free(succ);
                    }
                }
            }
        }
    }
}

int search_inList(list_t *list, void *x_key){
    if(list == NULL){
        printf("[WARNING @ search_inList] empty list\n");
        return 0;
    }
    else{
        if(list->head == NULL){
            printf("[WARNING @ search_inList] empty list\n");
            return 0;
        }
        else{
            elem_t *iter = list->head;
            int flag = 0;
            while((iter != NULL) && ((list->compare(x_key,iter->key))>=0) && (!flag)){
                if(!(list->compare(x_key,iter->key)))
                    flag = 1;
                iter = iter->next;
            }
            return flag;
        }
    }
}