lab6.c

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

typedef struct teams {
    char team[20];
    struct teams * next;
    struct comp * down;
} teams_list; 

typedef struct {
        char last_name[20];
        char first_name[20];
        char team[20];
        char sports_type[20];
        int all_pts;
        int penalty_pts;
} fields;

typedef struct comp {
        fields f;
        struct comp * next;
} competition; 

char file_name[] = "backup.txt";
teams_list * head = NULL;

void swap_elements(competition * el1, competition * el2) {
    fields swap = el1->f;
    el1->f = el2->f;
    el2->f = swap;   
}

void new_sort(int (*compare)(competition *, competition * )) {
    if (head == NULL) {
        printf("WARNING: List is empty.\n");
        return;    
    } 
    teams_list * current_parent = head;
    competition * temp;
    do {
        if (current_parent->down == NULL) continue;
        competition * current = current_parent->down, * next;
        int length=0;
        do {
            length++;
        } while ((current = current->next) != NULL);
        printf("INFO: team '%s' length is '%d'.\n",current_parent->team, length);
        int i, swap_cnt;
        for (i=0;i<length;++i) {
            swap_cnt = 0;
            current = current_parent->down;
            if (current->next == NULL) {
                printf("INFO: ARRAY CONTAINS ONE ELEMENT.\n");
                break;    
            }
            next = current->next;
            do {
                if (compare(current, next) > 0) {
                    swap_elements(current, next);
                }
                current = current->next;
                next = current->next;
            } while (next != NULL);
            if (swap_cnt == 0) break;
        }
    } while ((current_parent = current_parent->next) != NULL);    
}

teams_list * find_parent(char query[20]) {
    printf("INFO: called find_parent with '%s'.\n", query);
    
    teams_list * new_team = malloc(sizeof(teams_list));
    strcpy(new_team->team, query);
    new_team->next = NULL;
    new_team->down = NULL;
    printf("INFO: new team with value '%s' has created.\n", new_team->team);
    
    if (head == NULL) {
        printf("INFO: List is empty. Modify head.\n");
        head = new_team; 
        return new_team;   
    } else {
        printf("INFO: List is not empty. Attempt to search.\n");
        //printf("Current head team value is '%s'.\n", head->team);
        teams_list * current = head, * previous;
        do {
            if (strcmp(current->team, query) == 0) {
                printf("INFO: team '%s' already exists.\n", query);
                free(new_team);
                return current;  
            } 
            previous = current;
            current = current->next; 
        } while (current != NULL); 
            
        printf("INFO: team '%s' is not exists. Adding to list.\n", query); 
        previous->next = new_team;
        return new_team;
    }
}

void f_add(competition * el) {
    teams_list * parent;
    parent = find_parent(el->f.team);
    if (parent->down == NULL) {
        parent->down = el;    
    } else {
        competition * temp = parent->down;
        while (temp->next != NULL) temp = temp->next;
        temp->next = el; 
    }              
}

void f_input() {
    while (1) {
        competition * new_element = malloc(sizeof(competition));
        printf("Enter first name: \n");
        scanf(" %[^\n]", new_element->f.first_name);
        printf("Enter last name: \n");
        scanf(" %[^\n]", new_element->f.last_name);
        printf("Enter team: \n");
        scanf(" %[^\n]", new_element->f.team); 
        printf("Enter sports type: \n");
        scanf(" %[^\n]", new_element->f.sports_type);
        printf("Enter summary pts: \n");
        scanf(" %d", &new_element->f.all_pts); 
        printf("Enter penalty pts: \n");
        scanf(" %d", &new_element->f.penalty_pts); 
        new_element->next = NULL;
        f_add(new_element); //add element to list
        printf("DO YOU HAVE AGAIN?!! (y/n)\n");
        char answer;
        scanf(" %c", &answer);
        if (answer != 'y') return;
    }
}

void f_print() {
    if (head == NULL) {
        printf("WARNING: List is empty. Plz add new one.\n");
        return;    
    }
    int limit = 10;
    int index = 0;
    teams_list * current_parent = head;
    do {
        if (current_parent->down == NULL) continue;
        competition * temp = current_parent->down;
        do {
            ++index;
            printf("%02d|%10s|%10s|%10s|%10s|%5d|%5d|\n",
                index,
                temp->f.first_name,
                temp->f.last_name,
                temp->f.team,
                temp->f.sports_type,
                temp->f.all_pts,
                temp->f.penalty_pts); 
            if (index % limit == 0) {
                system("pause");    
            }   
        } while ((temp = temp->next) != NULL);
    } while ((current_parent = current_parent->next) != NULL);   
}

void f_delete(void) { //TO-DO: fix remove parent
    if (head == NULL) {
        printf("WARNING: List is empty. Plz add new one.\n");
        return;    
    }
    int removed;
    printf("Enter number element: \n");
    scanf(" %d", &removed);
    int index = 0;
    teams_list * current_parent = head, * previous_parent;
    do {
        if (current_parent->down == NULL) continue;
        competition * temp = current_parent->down, * previous;
        do {
            ++index;
            if (index == removed) {
                if (current_parent->down == temp && temp->next == NULL) {
                    free(temp);
                    free(current_parent);
                    if (head == current_parent && current_parent->next == NULL) {
                        head = NULL;
                    } else if (head == current_parent && current_parent->next != NULL) {
                        head = current_parent->next;
                    } else {
                        previous_parent->next = NULL;    
                    }    
                }
                if (current_parent->down == temp) {
                    current_parent->down = temp->next;
                    free(temp);    
                } else {
                    previous->next = temp->next;
                    free(temp);     
                }
                return;    
            }
            previous = temp;
            temp = temp->next; 
        } while (temp != NULL);
        previous_parent = current_parent;
        current_parent = current_parent->next;
    } while (current_parent != NULL); 
    printf("WARNING: ELEMENT NOT FOUND.\n");
}

void f_save(void) {
    if (head == NULL) {
        printf("List is empty. Nothing to save.\n");
        return;    
    } 
    FILE * backup = fopen(file_name, "w"); 
    teams_list * current_parent = head;
    do {
        if (current_parent->down == NULL) continue;
        competition * temp = current_parent->down;
        do {
            fprintf(backup, "%s|%s|%s|%s|%d|%d|\n",
                temp->f.first_name,
                temp->f.last_name,
                temp->f.team,
                temp->f.sports_type,
                temp->f.all_pts,
                temp->f.penalty_pts);
        } while ((temp = temp->next) != NULL);
    } while ((current_parent = current_parent->next) != NULL);  
    fclose(backup);
               
}

void f_restore(void) { 
    FILE * backup = fopen(file_name, "r");
    head = NULL;
    if (backup == NULL) {
        printf("File '%s' not found.\n", file_name);
        return;    
    }
    fields temporary_field;
    competition * previously;
    while (fscanf(backup, " %[^|]| %[^|]| %[^|]| %[^|]| %d| %d|\n", temporary_field.first_name, temporary_field.last_name, temporary_field.team, temporary_field.sports_type,  &temporary_field.all_pts, &temporary_field.penalty_pts) != EOF) {
        competition * new_element = malloc(sizeof(competition));
        new_element->next = NULL;
        new_element->f = temporary_field;
        
        teams_list * parent = find_parent(new_element->f.team);
        if (parent->down == NULL) {
            parent->down = new_element;    
        } else {
            competition * temp = parent->down;
            while (temp->next != NULL) temp = temp->next;
            temp->next = new_element; 
        }
        
    } 
    fclose(backup);           
}

void f_change(void) { 
    if (head == NULL) {
        printf("WARNING: List is empty. Plz add new one.\n");
        return;    
    }
    int changed;
    printf("Enter number element: \n");
    scanf(" %d", &changed);
    int index = 0;
    teams_list * current_parent = head;
    do {
        if (current_parent->down == NULL) continue;
        competition * temp = current_parent->down, * previous;
        do {
            ++index;
            if (index == changed) {
                printf("Enter field name to change :\n");
                char field_name[50];
                scanf(" %[^\n]", field_name);
                if (strcmp(field_name, "first_name") == 0) {
                        printf("Old value of '%s' param is '%s'\n", field_name, temp->f.first_name);
                        printf("Enter new value of '%s': \n", field_name);
                        scanf(" %[^\n]", temp->f.first_name);
                } else if (strcmp(field_name, "last_name") == 0) {
                        printf("Old value of '%s' param is '%s'\n", field_name, temp->f.last_name);
                        printf("Enter new value of '%s': \n", field_name);
                        scanf(" %[^\n]", temp->f.last_name);
                } else if (strcmp(field_name, "team") == 0) {
                        printf("Old value of '%s' param is '%s'\n", field_name, temp->f.team);
                        printf("Enter new value of '%s': \n", field_name);
                        scanf(" %[^\n]", temp->f.team);
                        f_add(temp);
                        previous->next = temp->next;
                        printf("INFO: RELOCATE DONE.\n");
                } else if (strcmp(field_name, "sports_type") == 0) {
                        printf("Old value of '%s' param is '%s'\n", field_name, temp->f.sports_type);
                        printf("Enter new value of '%s': \n", field_name);
                        scanf(" %[^\n]", temp->f.sports_type);   
                } else if (strcmp(field_name, "all_pts") == 0) {
                        printf("Old value of '%s' param is '%d'\n", field_name, temp->f.all_pts);
                        printf("Enter new value of '%s': \n", field_name);
                        scanf(" %d", &temp->f.all_pts);
                } else if (strcmp(field_name, "penalty_pts") == 0) {
                        printf("Old value of '%s' param is '%d'\n", field_name, temp->f.penalty_pts);
                        printf("Enter new value of '%s': \n", field_name);
                        scanf(" %d", &temp->f.penalty_pts);
                } else {
                        printf("Field name '%s' is not member of (first_name/last_name/team/sports_type/all_pts/penalty_pts) set.\n", field_name);           
                }
                return;   
            }
            previous = temp;
            temp = temp->next; 
        } while (temp != NULL);
    } while ((current_parent = current_parent->next) != NULL); 
    printf("WARNING: ELEMENT NOT FOUND.\n");
}

void terminate() {
    exit(0);    
}

int compare_ints(competition * el1, competition * el2) {
    if (el1->f.all_pts > el2->f.all_pts) return 1;
    if (el1->f.all_pts < el2->f.all_pts) return -1;
    return 0; 
    
}

int compare_strings(competition * el1, competition * el2) {
    return strcmp(el1->f.first_name, el2->f.first_name);   
}

void sort_1() {
    new_sort(compare_ints);    
}

void sort_2() {
    new_sort(compare_strings);    
}

int main() {
    while (1) {
        struct mn {
            char desc[100];
            void (*go)();
        } menu[] = {
            {"Add to list (console I/O)", f_input},
            {"View list (console I/O)", f_print},
            {"Save list", f_save},
            {"Restore list", f_restore},
            {"Delete element", f_delete},
            {"Sort by index field", sort_1},
            {"Sort by text field", sort_2},  
            {"Change values", f_change},
            {"Exit", terminate}
        };
        int menu_cnt = 9, i;
        system("cls");
        for (i=0;i<menu_cnt;++i) {
            printf("%d : %s\n", i, menu[i].desc);    
        }
        printf("Choose your destiny: ");
        int choose;
        ;
        if (scanf(" %d", &choose) != 1 || choose >= menu_cnt) {
            printf("ERROR! Invalid menu point.\n");
            system("pause");
        }
        system("cls");
        menu[choose].go();
        system("pause");
    }
    return 0;        
}