/* 
* Code example for CP264 Data Structures II
* test union
* HBF 
*/
#include <stdio.h>
#include <string.h>

typedef union {
  int id;
  double score;
} RECORD;

void display(RECORD a, int i){
  if (i==0) 
    printf("%d\n", a.id); 
  else
	printf("%f\n", a.score); 
}

RECORD inc(RECORD a, int i){
  if (i==0) 
    a.id += 1; 
  else
    a.score += 1; 
  return a;
}

int main() {
  printf("sizeof(RECORD):%d\n", sizeof(RECORD)); 
 
  RECORD a;
  printf("address_a.:%lu\n", &a); 
  printf("address_a.id:%lu\n", &a.id);
  printf("address_a.score:%lu\n", &a.score);
  
  a.id = 12; 
  int rid = a.id;
  printf("%d\n", a.id);      // output: 12  
  printf("%d\n", rid);       // output: 12
  printf("%f\n", a.score);   // not meaningful 
  
  a.score = 88.34; 
  printf("%d\n", a.id);      // not meaningful  
  printf("%f\n", a.score);   // output:88.340000  
  display(a, 1);

  RECORD b = a;
  display(b, 1);
  
  RECORD c = inc(b, 1);
  display(c, 1);
  
  RECORD *p = &a;
  printf("%f\n", p->score); 

  return 0;
}

/*
izeof(RECORD):8
address_a.:6422272
address_a.id:6422272
address_a.score:6422272
12
12
0.000000
-1889785610
88.340000
88.340000
88.340000
89.340000
88.340000
*/