Thread: Modifying parallel arrays to arrays of structures

I been away from C programming for awhile now, and it's difficult for me to figure this out. The program itself works, however I am supposed to turn this code into an array of structures instead of having 3 parallel arrays.

I heard it doesn't take long if you already have a working set of code.

Code:

#include <stdio.h>  // preprocessor directive to allow use of printf()/sca$
#include <string.h> //preprocessor directive to allow use of strings
   
 //typedef below used to create a structure tag for structure definitions
typedef struct person { //Algorithm step 2
                       char first_name[20]; //array "first_name"element
    
                       //Algorithm step 3
                       char last_name[20]; //array "last_name"element
       
                       //Algorithm step 4
                       char age[4]; //array "age" element
 
                       }ppl ; //tag name
 
  
 void populate (ppl []); //PCF populate prototype
 void last_name_sort (ppl []); //PCF last_name_sort prototype
  
 int main (void ) //Main function- returns and integer/ accepts no argumen$
 { //Marks beginning of the main function's statement
   int i; //integer i created and initialized
   
   //Algorithm step 1 completed in next four lines
   printf("Hello! \nThe purpose of this program is to use parallel arrays $
   printf("order the names aphabetically (by last name) without mixing the$
   printf("names and ages. The newly sorted information will be printed to$
   printf("screen. \n\n\n\n");
   
   ppl person[7]; //defined structure "person"
 
   populate (person); //defined structure passed to PCF populate
 
    last_name_sort (person); //defined structure passed to PCF last_name_s$
    printf("\n\n<-------------------------~SORTED LIST~-------------------$
    for (i=0; i<= 6; i++)
    {
       //Algorithm step 8 in for loop
       printf("%s %s %s\n", person[i].first_name , person[i].last_name, pe$
    }
  
 printf("\n\n\n");
 printf("Thank you for using my program. I hope it was helpful!\n\n");
 return (0) ;
 }
 
 void populate (ppl person[])
 {
 int i; //creation of integer variable i
 
   printf("Please enter a first name, last name, and age with a space in b$
   printf("and the first letter of the first and last name capitalized: \n$
   printf("\n\n<-----------------------~UNSORTED LIST~--------------------$
 
  for (i=0; i<= 6; i++)
  {
   scanf("%s %s %s",person[i].first_name , person[i].last_name, person[i].$
  }
 
 return;
 }
 void last_name_sort( ppl person[])
 {
 int i, j;
 char temp[20]; //creation of first temporary array for 3way switch of las$
 char temp_1[20]; //creation of first temporary array for 3way switch of f$
 char temp_2[4]; //creation of first temporary array for 3way switchof age
 
 for (i=0; i<=5; i++) //outer for loop
 {
 for(j=0; j<=5; j++) //inner "nested" for loop
 {
 if (strncmp(person[j].last_name, person[j+1].last_name, 7) >0)
 {
 //Algorithm for last name sorting
 strcpy (temp, person[j].last_name);
 strcpy (person[j].last_name, person[j+1].last_name);
 strcpy (person[j+1].last_name, temp);
 
 //Algorithm so first name follows where last name is sorted
 strcpy (temp_1, person[j].first_name);
 strcpy (person[j].first_name, person[j+1].first_name);
 strcpy (person[j+1].first_name, temp_1);
 
 //Algorithm  so age follows where last name is sorted
 strcpy (temp_2, person[j].age);
 strcpy (person[j].age, person[j+1].age);
 strcpy (person[j+1].age, temp_2);
 }
 }
  
 return;
 }
}

Any tip, help or comment would be great!
Thank you.