I am making an uno card game with structure of card with fields:
struct card
{
int rank
char *color
char *action.
}
I am able to make it sort by color with insertion. I wonder how could I first sort the array of uno card by color, then sort the rank of each color.
Thanks to Bo Persoson, this is the solution to my question
void sort(card *a, int length) {
int j;
for (int i = 1; i < length; i++) {
j = i;
while (j > 0 && a[j].color < a[j - 1].color || (a[j].color == a[j - 1].color && a[j].rank < a[j - 1].rank)) {
swap(&a[j], &a[j - 1]);
j--;
}
}
}
Assuming you are overloading the operator <, you should implement a condition that compares the color of the cards and their rank. Since you want that the primary sorting criteria will be the color you should check that one first. I would implement it something like this:
int colorCompareResult = strcmp(card1.color, card2.color);
if (colorCompareResult < 0)
return true;
else if (colorCompareResult == 0 && card1.rank < card2.rank)
return true;
else
return false;
Let's assume that the structure is called card and c1 and c2 are two pointers to objects of the structure.
In this case you should use the following condition to compare elements of the array
int comparison( card *c1, card *c2 )
{
int color_cmp = strcmp( c1->color, c2->color );
return color_cmp < 0 || ( color_cmp == 0 && c1->rank < c2->rank );
}
This predicate is considered as a boolean predicate. If you need a comparison function thet will be used in the standard algorithm qsort then you have to change it such a way that it returns -1, 0 or 1.
For example
int comparison( const void *p1, const void *p2 )
{
const card *c1 = ( const card * )p1;
const card *c2 = ( const card * )p2;
int color_cmp = strcmp( c1->color, c2->color );
if ( color_cmp < 0 )
{
return -1;
}
else if ( color_cmp > 1 )
{
return 1;
}
else
{
return ( c2->rank < c1->rank ) - ( c1->rank < c2->rank );
}
}
color1 < color2, you can change that tocolor1 < color2 || (color1 == color2 && rank1 < rank2).