Problem with Pointers and an Array

[thetinman]

I have some code that just does seem to work right. The code looks like this

#include <stdio.h>
#include <math.h>

int main() {
	double a=1, b=1, *r;
	int i=2, n=10;
	r = malloc(n);
	r[0] = 1; 
	
	while(i<n){
		if( i%4 == 0){
			a +=  1;
			b += 2;
		}
		else if( i%2 == 0){
			a += 3;
			b += 4;
		}
			
		r[i-1] = a;			
		r[i] = b;		

		i += 2;
		
	}
	
    for(i = 0; i<n; i++){
	 printf("r[%d] = %f \n",i, r[i]);   
    }  
	    
return 0;       
}

It should output something that looks like this

1
2
3
5
7
6
9
8
11

Instead it outputs

1
0
0
0
0
0
0
0

Which is clearly not what I want.

Does any one know how I can make this code work? What is wrong with it? I suspect it has something to do with my pointers, but I'm not positive.

[Salem]

> r = malloc(n);
This allocates 10 bytes, not 10 doubles.

r = malloc ( n * sizeof *r );

Also, you didn't include stdlib.h. Did this compile without warnings?