Thread: Family tree

So I've built a simple code that basically function as a family tree, but there's always an issue when it comes to marrying two people or printing the cousins. PLEASE HELP

Code:

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

#define MAX_NAME_LENGTH 50

typedef struct Person {
  char name[MAX_NAME_LENGTH];
  int age;
  struct Person *spouse;
  struct Person *child;
} Person;

// Function prototypes
void addHead(Person ** family);
void marry(Person ** family);
void addOffspring(Person ** family);
void printFamily(Person ** family);
void yearsPass(Person ** family);
void countPeople(Person ** family);
void printCousins(Person ** family);

void printCousinsRecursive(Person * person, int targetDegree,
                           int currentDegree);
void printSiblings(Person * sibling, int targetDegree, int currentDegree);
void freeFamily(Person ** family);

int main()
{
  int choice;
  Person *family = NULL;

  do {
    printf("Choose an option:\n");
    printf("0. Exit\n");
    printf("1. Add a head\n");
    printf("2. Marry two people\n");
    printf("3. Add an offspring\n");
    printf("4. Print family top-down\n");
    printf("5. Years pass\n");
    printf("6. Count people\n");
    printf("7. Print cousins\n");
    scanf("%d", &choice);

    switch (choice) {
    case 0:
      break;
    case 1:
      addHead(&family);
      break;
    case 2:
      marry(&family);
      break;
    case 3:
      addOffspring(&family);
      break;
    case 4:
      printFamily(&family);
      break;
    case 5:
      yearsPass(&family);
      break;
    case 6:
      countPeople(&family);
      break;
    case 7:
      printf("Cousins:\n");
      printCousins(&family);
      printf("\n");
      break;
    default:
      printf("Invalid option\n");
      break;
    }

  } while (choice != 0);

  freeFamily(&family);

  return 0;
}

void freeFamily(Person ** family)
{
  Person *current = *family;
  while (current != NULL) {
    Person *nextPerson = current->child;

    // Free the current person
    free(current);

    // Move to the next person
    current = nextPerson;
  }

  // Set the family pointer to NULL
  *family = NULL;
}

void addHead(Person ** family)
{
  char name[MAX_NAME_LENGTH];
  int age;

  getchar();
  printf("Enter a name:\n");
  fgets(name, sizeof(name), stdin);
  name[strcspn(name, "\n")] = '\0';

  // Check if the name is already taken
  if (*family != NULL && strcmp((*family)->name, name) == 0) {
    printf("The name is already taken\n");
    return;
  }

  printf("Enter age:\n");
  scanf("%d", &age);

  // Create a new person
  Person *head = (Person *) malloc(sizeof(Person));
  strcpy(head->name, name);
  head->age = age;              // Store the entered age
  head->spouse = NULL;
  head->child = NULL;

  // Set the new person as the family head
  *family = head;
}

void marry(Person ** family)
{
  getchar();
  char name1[MAX_NAME_LENGTH], name2[MAX_NAME_LENGTH];
  printf("Enter the name of the first person:\n");
  fgets(name1, sizeof(name1), stdin);
  name1[strcspn(name1, "\n")] = '\0';
  printf("Enter the name of the second person:\n");
  fgets(name2, sizeof(name2), stdin);
  name2[strcspn(name2, "\n")] = '\0';

  // Find the first person
  Person *person1 = *family;
  while (person1 != NULL && strcmp(person1->name, name1) != 0)
    person1 = person1->child;

  // Find the second person
  Person *person2 = *family;
  while (person2 != NULL && strcmp(person2->name, name2) != 0)
    person2 = person2->child;

  // Check if both persons were found
  if (person1 == NULL || person2 == NULL) {
    printf("One of the persons does not exist\n");
    return;
  }
  // Check if one of them is already married
  if (person1->spouse != NULL || person2->spouse != NULL) {
    printf("Invalid marriage\n");
    return;
  }
  // Check if they have a common previous head (same family)
  Person *commonHead = *family;
  while (commonHead != NULL
         && (commonHead->child == NULL
             || (commonHead->child != person1 && commonHead->child != person2)))
    commonHead = commonHead->child;

  if (commonHead != NULL) {
    printf("Invalid marriage\n");
    return;
  }
  // Check if one of them is under the age of 18
  if (person1->age < 18 || person2->age < 18) {
    printf("Invalid marriage\n");
    return;
  }
  // Update the spouse pointers
  person1->spouse = person2;
  person2->spouse = person1;

  printf("%s and %s are now married\n", person1->name, person2->name);
}

void addOffspring(Person ** family)
{
  getchar();
  char parent1[MAX_NAME_LENGTH], parent2[MAX_NAME_LENGTH],
      offspring[MAX_NAME_LENGTH];
  printf("Enter the name of the first parent:\n");
  fgets(parent1, sizeof(parent1), stdin);
  parent1[strcspn(parent1, "\n")] = '\0';

  printf("Enter the name of the second parent:\n");
  fgets(parent2, sizeof(parent2), stdin);
  parent2[strcspn(parent2, "\n")] = '\0';

  printf("Enter offspring's name:\n");
  fgets(offspring, sizeof(offspring), stdin);
  offspring[strcspn(offspring, "\n")] = '\0';

  // Find the first parent
  Person *person1 = *family;
  while (person1 != NULL && strcmp(person1->name, parent1) != 0)
    person1 = person1->child;

  // Find the second parent
  Person *person2 = *family;
  while (person2 != NULL && strcmp(person2->name, parent2) != 0)
    person2 = person2->child;

  // Check if both parents were found
  if (person1 == NULL || person2 == NULL) {
    printf("One of the parents does not exist\n");
    return;
  }
  // Check if the parents are married
  if (person1->spouse != person2 || person2->spouse != person1) {
    printf("The parents are not married\n");
    return;
  }
  // Check if the offspring's name is already taken
  Person *existingPerson = *family;
  while (existingPerson != NULL) {
    if (strcmp(existingPerson->name, offspring) == 0) {
      printf("The name is already taken\n");
      return;
    }
    existingPerson = existingPerson->child;
  }

  // Create a new offspring
  Person *newOffspring = (Person *) malloc(sizeof(Person));
  strcpy(newOffspring->name, offspring);
  newOffspring->spouse = NULL;
  newOffspring->child = NULL;

  // Set the new offspring's parents
  newOffspring->child = person1->child;
  person1->child = newOffspring;

  printf("%s was born\n", newOffspring->name);
}

void printFamily(Person ** family)
{
  char name[MAX_NAME_LENGTH];
  printf("Enter the name of the person:\n");
  fgets(name, sizeof(name), stdin);
  name[strcspn(name, "\n")] = '\0';

  // Find the person
  Person *person = *family;
  while (person != NULL && strcmp(person->name, name) != 0)
    person = person->child;

  // Check if the person was found
  if (person == NULL) {
    printf("Person not found\n");
    return;
  }
  // Print the person and their family
  printf("%s (%d)", person->name, person->age);

  if (person->spouse != NULL) {
    printf(" - %s (%d)\n", person->spouse->name, person->spouse->age);

    Person *child = person->child;
    while (child != NULL) {
      printf("\t%s (%d)\n", child->name, child->age);
      child = child->child;
    }
  } else {
    printf("\n");
  }
}

void yearsPass(Person ** family)
{
  int years;
  printf("Enter number of years:\n");
  scanf("%d", &years);

  // Traverse the family tree and add years to each person's age
  Person *current = *family;
  while (current != NULL) {
    current->age += years;
    current = current->child;
  }

}

void countPeople(Person ** family)
{
  int count = 0;

  // Traverse the family tree and count the number of people
  Person *current = *family;
  while (current != NULL) {
    count++;
    current = current->child;
  }

  // Print the count of people
  if (count == 1) {
    printf("There is one person\n");
  } else {
    printf("There are %d people\n", count);
  }
}

void printCousins(Person ** family)
{
  char name[MAX_NAME_LENGTH];
  int degree;

  printf("Enter the name of the person:\n");
  scanf("%s", name);
  printf("Enter degree:\n");
  scanf("%d", &degree);

  // Find the person
  Person *person = *family;
  while (person != NULL && strcmp(person->name, name) != 0)
    person = person->child;

  // Check if the person was found
  if (person == NULL) {
    printf("Person not found\n");
    return;
  }
  // Print the person
  printf("%s\n", person->name);

  // Print cousins of the specified degree
  printCousinsRecursive(person, degree, 1);
}

void printCousinsRecursive(Person * person, int targetDegree, int currentDegree)
{
  if (currentDegree > targetDegree)
    return;

  Person *current = person;
  while (current != NULL) {
    if (current->spouse != NULL) {
      printSiblings(current->spouse->child, targetDegree, currentDegree);
    }
    current = current->child;
  }
}

void printSiblings(Person * sibling, int targetDegree, int currentDegree)
{
  while (sibling != NULL) {
    if (currentDegree <= targetDegree) {
      printf("%s\n", sibling->name);
      printCousinsRecursive(sibling, targetDegree, currentDegree + 1);
    }
    sibling = sibling->child;
  }
}