In c/c++ programming Add additional functionality to your phonebook program from lab# 7. Make it possible for users to: 1) Store all entries in the phonebook into a location/file-name specified by the user. 2) Retrieve entries from the location/file-name specified by the user. If the user does not explicitly specify a path to the file, a default location of your choosing should be used. Here is my current coplease add. #include #include #include // create a struct struct phonebook{ char fname[20]; char lname[20]; char phone[8]; }; void addfriend(struct phonebook **, int *); void deletefriend(struct phonebook **, int); void showPhonebook(struct phonebook **); //four new methods added void sortByFirstName(struct phonebook **); void findNumber(struct phonebook **); void randomSelect(struct phonebook **); void deleteAll(struct phonebook **); int main() { int i; // create an array of type struct phonebook struct phonebook **arr = (struct phonebook **)malloc(50 * sizeof(struct phonebook *)); // index at which new entry is to be added int index = 0; // set all entries of arr to NULL for( i = 0 ; i < 50 ; i++ ) arr[i] = NULL; while(1) { printf("Enter one of the following options ... "); printf("1) Add friend 2) Delete friend 3) Show phone book 4) Sort By First Name 5) Find phobe number 6) Random Friend 7) Delete all 8) Quit "); int option; scanf("%d",&option); switch(option) { case 1 : addfriend(arr, &index); break; case 2 : deletefriend(arr, index); break; case 3 : showPhonebook(arr); break; case 4 : sortByFirstName(arr); break; case 5 : findNumber(arr); break; case 6 : randomSelect(arr); break; case 7 : deleteAll(arr); break; case 8 : sortByFirstName(arr); exit(0); default : printf("Invlid choice , try again ! "); exit(0); } } return 0; } void addfriend(struct phonebook **arr, int *index) { struct phonebook *temp = (struct phonebook *)malloc(sizeof(struct phonebook)); printf("Enter the name of friend "); scanf("%s%s", temp->fname, temp->lname); printf("Enter the phone number "); scanf("%s", temp->phone); arr[*index] = temp; (*index)++; } void deletefriend(struct phonebook **arr, int index) { char f[20], l[20]; printf("Enter the name of friend "); scanf("%s%s", f, l); int i; // find the required contact for( i = 0 ; i < 50 ; i++ ) // if contact is found if(arr[i] && !strcmp(arr[i]->fname, f) && !strcmp(arr[i]->lname, l)) // set that element to NULL arr[i] = NULL; } void showPhonebook(struct phonebook **arr) { int i; for( i = 0 ; i < 50 ; i++ ) // if element is not NULL if(arr[i]) printf("Name : %s %s Phone Number : %s ",arr[i]->fname, arr[i]->lname, arr[i]->phone); } //funtion to sort by first name void sortByFirstName(struct phonebook **arr) { int i,j; //three char pointer for storing the temp data char *temp1= (char*)malloc(sizeof(char)*20); char *temp2=(char*)malloc(sizeof(char)*20); char *temp3=(char*)malloc(sizeof(char)*8); for(i=0;i<50;i++) { if(arr[i]) for(j=i+1;j<50;j++) { if(arr[j]) if(strcmp(arr[j]->fname,arr[i]->fname)<0)//comparing the name { strcpy(temp1,arr[j]->fname);//copying to temp strcpy(temp2,arr[j]->lname); strcpy(temp3,arr[j]->phone); strcpy(arr[j]->fname,arr[i]->fname);//changin array index value strcpy(arr[j]->lname,arr[i]->lname); strcpy(arr[j]->phone,arr[i]->phone); strcpy(arr[i]->fname,temp1); strcpy(arr[i]->lname,temp2); strcpy(arr[i]->phone,temp3); } } } showPhonebook(arr);//printing tha names } void findNumber(struct phonebook **arr) { char f[20], l[20]; printf("Enter the name of friend "); scanf("%s%s", f, l); int i; for( i = 0 ; i < 50 ; i++ ){ //if name found if(arr[i] && !strcmp(arr[i]->fname, f) && !strcmp(arr[i]->lname, l)){ //printing the name printf("Phone number : %s ",arr[i]->phone); return; } }//if name not found printf("Name not found "); } //method to select random friend void randomSelect(struct phonebook **arr) { int i; //in loop while(1){ //generting rand no in between 0-50 i = rand() % 50; if(arr[i])//if not null { printf("Name : %s %s Phone Number : %s ",arr[i]->fname, arr[i]->lname, arr[i]->phone); break; } } } //method to dlete all names void deleteAll(struct phonebook **arr){ int i; for( i = 0 ; i < 50 ; i++ ) arr[i] = NULL; }