Поиск машины по любой комбинации из признаков

#include <stdio.h>
#include <malloc.h>
#include <string.h>
void main()
{
struct cars
{
struct data  //Дата регистрации
{
int dd;  //день
int mm;  //месяц
int gg;  //год
};
struct data DATA;
char mark[25];   //Марка машины
int year;    //Год выпуска
char color[10];  //цвет
char number[10];     //номер
};
struct cars CARS[20];
int n,i;
char an;
 
printf("==========Register a new car==========\n\n");   
printf("============================================\n");
printf("To exit the registration, press 0\n");
printf("To continue, press 1:");
scanf("%d",&n); 
printf("============================================\n");
i=0;
while((n!=0)&&(i!=20))
{
printf("\nDay of registration:");
printf("\nDay:");
scanf("%d",&CARS[i].DATA.dd);
printf("\nMonth:");
scanf("%d",&CARS[i].DATA.mm);
printf("\nYear:");
scanf("%d",&CARS[i].DATA.gg);
printf("\nEnter the brand of car:");
scanf("%s",&CARS[i].mark);
printf("\nEnter the year of manufacture:");
scanf("%d",&CARS[i].year);
printf("\nEnter color:");
scanf("%s",&CARS[i].color);
 
printf("\nEnter Number:");
scanf("%s",&CARS[i].number);
printf("============================================\n");
printf("To exit the registration, press 0\n");
printf("To continue, press 1:");
scanf("%d",&n);
printf("============================================\n");
 
i++;
}
for(i=0;i<3;i++)
{
printf("============================================\n");
printf("\nNumber on list:%d\n",i);
printf("\nDay of registration:");
printf("\nDay:%d;\nMonth:%d;\nYear:%d;",CARS[i].DATA.dd,CARS[i].DATA.mm,CARS[i].DATA.gg);
printf("\nThe brand of car:%s",CARS[i].mark);
printf("\nThe year of manufacture:%d",CARS[i].year);
printf("\nColor:%s",CARS[i].color);
printf("\nNumber:%s",CARS[i].number);
printf("\n============================================\n");
}
char ch[2];
an='g';
printf("Do you want to remove the car from the list?\n");
printf("(Y/N):\n");
scanf("%s",ch);
if(ch[0]=='Y'|| ch[0]=='y')
{
char a[25]=" ";
printf("Enter number on list:");
scanf("%d",&i);
CARS[i].DATA.dd=0;
CARS[i].DATA.mm=0;
CARS[i].DATA.gg=0;
strncpy(CARS[i].mark,a,25);
strncpy(CARS[i].color,a,10);
strncpy(CARS[i].number,a,10);
CARS[i].year=0;
}   
else
{
printf("\nErrOr\n");
return;
}
for(i=0;i<3;i++)
{
printf("============================================\n");
printf("\nNumber on list:%d\n",i);
printf("\nDay of registration:");
printf("\nDay:%d;\nMonth:%d;\nYear:%d;",CARS[i].DATA.dd,CARS[i].DATA.mm,CARS[i].DATA.gg);
printf("\nThe brand of car:%s",CARS[i].mark);
printf("\nThe year of manufacture:%d",CARS[i].year);
printf("\nColor:%s",CARS[i].color);
printf("\nNumber:%s",CARS[i].number);
printf("\n============================================\n");
}
 
 
 
 
}