Printing a triangle with 3 different symbols - c

Question

I've been sent a exercise where I have to print to the console (in C) a triangle using three different symbols in the following way:
The program must ask how many rows the triangle will have.
The program will print the triangle in the following way:
From outside to inside, the first triangle will be formed of *, the one inside it will be -, the one inside again will be $ and then the other way around...
This is my code:
#include <stdio.h>
int num = 0; //Var to store the user input.
int blank; //Var to store number of blank spaces.
int main() {
printf("Number of rows? ");
scanf("%d", &num);
printf("\n");
blank = num - 1;
//For loop to print each row of the triangle.
for(int k = 1; k <= num; k++) {
//For loop to print each blank space.
for(int j = 1; j <= blank; j++) {
printf(" ");
}
blank--; //Decrease number of blank spaces.
//For loop to print each symbol of the triangle.
for(int r = 1; r <= 2 * k - 1; r++) {
if(r % 2 == 0) {
printf("-");
}
else if(r % 3 == 0) {
printf("$");
}
else {
printf("*");
}
}
printf("\n");
}
blank = 1;
return 0;
}
And this is what it's printing:

Answer 1

Try working out the pattern on paper first.
For example, the dollar sign starts two rows below the top of the outermost triangle. All subsequent dollar signs are each one column before or one column after the preceding dollar sign. In this way each character of a new line is remotely dependent on the very first character.
Once you understand the underlying pattern, you can start programming the loop.