#include <stdio.h>

/*
    Problem 1 -(To get you started) ... a program in C which 
    gets 3 integers from the user, via the keyboard, and then
    displays the minimum, middle and maximum integers in order.
    
    We can use a simple bubble sort for ordering the numbers.

    Note: C doesn't support passing by ref so easily as C++ does ...
    
    We must pass the address in ... of the object being passed
    Then 'catch' that address as a 'pointer' (i.e. an address) for the object

*/

/* Here ... we tell the compiler that a,b,c are all addresses for int's */ 
void sort(int* a, int* b, int* c)
{
    int temp;
    /* 
        using a BUBBLE SORT: first ... 'bubble' the highest to c 
        then 'bubble' the next highest to b ... and we are done  
        
        NOTE: below ... 
        *a and *b take the int values at addresses a and b
        since on the top line we told the compiler 
        that a and b were pointers to (i.e. addresses for) 'int'
    */
    if( *a > *b ) /* if value at address a > value at address b then swap */
    {
        temp = *a;
        *a = *b;
        *b = temp;
    }
    if( *b > *c ) /* swap */
    {
        temp = *b;
        *b = *c;
        *c = temp;
    }
    if( *a > *b ) /* swap */
    {
        temp = *a;
        *a = *b;
        *b = temp;
    }
 
}
     
int main()
{
    int a=0, b, c, t;
    for(;;)
    { 
        printf( "Input 3 non zero integers to be ordered : " );
        a=b=c=0; /* use these zeros as flags for bad data input */ 
        scanf( "%d%d%d", &a, &b, &c );
        while(  (t=getchar()) != '\n' ) ; /* flush stdin */
        
        /* check for bad data ...  */
        if( a==0 || b==0 || c== 0 )
        {
            printf("\nIntegers only ...  ");
            continue; /* from the top of the for loop ...*/
        }
        
        sort( &a, &b, &c ); /* pass addresses to sort function */
        
        printf( "Now in order %d %d %d\n\n", a, b, c );
        
        printf("Press 'Enter' to continue ... 'x' to exit ... ");
        t =getchar();
        if ( t=='x' || t=='X' ) return 0;
        if ( t !='\n') while( (t=getchar()) != '\n' ) ; /* flush stdin */
    }
}