Program to invert 'n' alternate bits of a number (Asked in APPLIED MATERIALS coding round)

// initial 30 = 11110
// final   11 = 01011

#include<stdio.h>
int invert_alternate_bit(int,int);
int main()
{
printf("NEW num : %d\n",invert_alternate_bit(30,3));
return 0;
}
int invert_alternate_bit(int num,int n)
{
int c = 0;
printf("OLD num : %d\n",num);
for(int i=1; i<= n ; i++)
{
c = c << 2;
c = c ^ 1;
}
num = num ^ c;
return num;
}