new with search

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
FILE *fb,*fp;
int position=0,n;
int searcharr[100];
typedef struct birth //defining birthday date
{
    int day;
    int month;
    int year;
}birth;
birth readbirthday() //function for reading birthday from file (used in readcontact() function)
{
    birth birthday;
    fscanf(fb,",%d",&birthday.day);
    fscanf(fb,"/%d",&birthday.month);
    fscanf(fb,"/%d",&birthday.year);
    return birthday;
}

typedef struct contact //defining contacts and its fields
{
    char firstname[20];
    char lastname[20];
    birth birthday;
    char address[50];
    char city[20];
    int phonenumber;
}contact;
contact readcontact()
{
    contact contacts;
    FILE * fb = fopen("book.txt","r");
    fseek(fb,position,0);
    fscanf(fb,"%[^,]",contacts.firstname);
    fscanf(fb,",%[^,]",contacts.lastname);
    fscanf(fb,",%d",&contacts.birthday.day);
    fscanf(fb,"/%d",&contacts.birthday.month);
    fscanf(fb,"/%d",&contacts.birthday.year);
    fscanf(fb,",%[^,]",contacts.address);
    fscanf(fb,",%[^,]",contacts.city);
    fscanf(fb,",%d\n",&contacts.phonenumber);
    position = ftell(fb);
    fclose(fb);
    return contacts;
}
void printcontact(contact contacts)
{
    printf("\nFirst name is: %s\n",contacts.firstname);
    printf("Last name is: %s\n",contacts.lastname);
    printf("Birthday: %d/%d/%d\n",contacts.birthday.day,contacts.birthday.month,contacts.birthday.year);
    printf("Address: %s\n", contacts.address);
    printf("City: %s\n",contacts.city);
    printf("Phone number: 0%d\n",contacts.phonenumber);

}
void add_contact()
{
    contact Contact;
    fp = fopen("book.txt","a");
    printf("Enter the contact's first name\t:");
    scanf("%s",Contact.firstname);
    fprintf(fp,"%s,",Contact.firstname);
    printf("Enter the contact's last name\t:");
    scanf("%s",Contact.lastname);
    fprintf(fp,"%s,",Contact.lastname);
    printf("Enter the birth date\n");
    printf("enter the day:\t");
    scanf("%d",&Contact.birthday.day);
    fprintf(fp,"%d/",Contact.birthday.day);
    printf("enter the month\t:");
    scanf("%d",&Contact.birthday.month);
    fprintf(fp,"%d/",Contact.birthday.month);
    printf("enter the year\t:");
    scanf("%d",&Contact.birthday.year);
    fprintf(fp,"%d,",Contact.birthday.year);
    printf("Enter the address: ");
    scanf(" %199[^\n]",Contact.address);
    fprintf(fp,"%s,",Contact.address);
    printf("Enter the city: ");
    scanf("%s",Contact.city);
    fprintf(fp,"%s,",Contact.city);
    printf("Enter phone number\t:");
    scanf("%d",&Contact.phonenumber);
    fprintf(fp,"%d\n",Contact.phonenumber);

    fclose(fp);
}
int count_contacts()
{
    int count=0;
    fb = fopen("book.txt","r");
    while(!feof(fb))
    {
        char c;
        if((c=fgetc(fb))=='\n')
            count++;
    }
    fclose(fb);
    return count;
}
void display_menu()
{
    int x;
    printf("***********\n*Phonebook*\n***********\n\nWhat do you want?\n1-Add contact\n2-Delete\n3-Modify\n4-Search\n5-Print\n6-Save\n7-Quit\nPlease enter a number: ");
    scanf("%d",&x);
    switch(x)
    {
        case(1): add_contact();break;
        case(2): printf("add");
        case(3): printf("add");
        case(4): printf("add");
        case(5): ;break;
        case(7): printf("add");break;
        case(8): printf("add");break;
        case(9): printf("add");break;

    }
}
int substring(char name[],char key[])
{
    int i,j,flag;
    for(i=0;i<=strlen(name)-strlen(key);i++)
    {

        for(j=0;j<strlen(key);j++)
        {
            flag = 1;
        if(key[j] != name[j+i])
        {
            flag = 0;
            break;
        }

        }
        if (flag ==1)
            break;


    }
    return flag;
}
/*int* searchcontact(char name[],char key[])
{
    int i,j=0,n;
    int* arr = (int*) malloc(10*sizeof(int));
    printf("Enter the search key");
    scanf("%s",key);
    printf("%s",key);
    for(i=0;i<count;i++)
    {
        if(substring(contacts[i].firstname,key))
        {
           printf("contact found");
           arr[j]=i;
           j++;
           n=j;
        }
    }
    if(j==0)
    {
        printf("contact not found");
        return 0;
    }
    return arr;

}*/
int main()
{
//    display_menu();
    int i,j=0;
    char key[20];
 //   add_contact();
    int count = count_contacts();
    contact contacts[count];
    for(i=0;i<count;i++)
    contacts[i] = readcontact();
//    int* arr = (int*) malloc(count*sizeof(int));

    printf("Enter the search key: ");
    scanf("%s",key);
   // printf("%s",key);
    for(i=0;i<count;i++)
    {
        if(substring(contacts[i].firstname,key))
           {
              //  printf("contact found");
                searcharr[j]=i;
                j++;
                n=j;
           }
    }
    if(j==0)
        printf("Search not found");
    if(j!=0)
    for(j=0;j<n;j++)
        printcontact(contacts[searcharr[j]]);


    /*for(i=0;i<count;i++)
    {
        printf("\nContact number %d:\n",i+1);
        printcontact(contacts[i]);

    }*/

    return 0;
}