C Pointer problem

Can anybody please tell me why this code prints "9 5 2"?
I am am really frustrated about this. So your help is very appreciated...

#include <stdlib.h>
#include <stdio.h>

struct vec3{
       double x, y, z;       
};

typedef struct vec3 * ps_vec3;


int main(){
 char i;

 ps_vec3 a;
 ps_vec3 b;
 ps_vec3 c;

 if((a = (ps_vec3) malloc(sizeof(ps_vec3))) == NULL){
       exit(1);      
 }

 if((b = (ps_vec3) malloc(sizeof(ps_vec3))) == NULL){
       exit(1);      
 }
 
 if((c = (ps_vec3) malloc(sizeof(ps_vec3))) == NULL){
       exit(1);      
 }
 
 //b-z = c-x

 b->x = 9;
 b->y = 5;
 b->z = 7;
 c->x = 2;
 c->y = 77;
 c->z = 65;

 printf("%lf %lf %lf", b->x, b->y, b->z);
 
 free(a);
 free(b);
 free(c);
 return 0;
}

Code (markup):

 

//b-z = c-x
Recompile and run.

 

because u do this "b-z = c-x",As a result now b->z have the value of c->x;
if u can't solve this prob,then pm me.

 

b-z = c-x is not the problem since it is commented out.
the problem is that memory allocation is the size of a pointer. The amount of memory allocated should be the size of the struct, not the pointer.

 

surprise..

malloc(sizeof(pointer)) = 4bytes

malloc(sizeof(notapointer)) = size of the struct
malloc(sizeof(struct vec3)) = size of the struct