Recursivity

[candexis]

Well I need to implement a recustivity function to calculate the Rc value of a vactor Rcon, whinc is define like this: Rcon[i] = (RC[i]; 0; 0; 0), each element of the vector is one byte. And the only non-zero byte in the round constants obeys the following recursive formula: So I only need to calculate Rc[i], according to the following formula:

RC[1] = 1
RC[j] = 2 * RC[j - 1]

for example, if i = 1, then Rc[1] = 1; if i = 2, then Rc[2] = 2, if i = 3, then Rc[3] = 4, and so on,

Thanks for your help.

[pukur123]

Try the following program....


#include<stdio.h>

int rc(int);

int main()
{
int num;
printf("Enter a number ");
scanf("%d",&num);
printf("Result is %d\n",rc(num));
return 0;
}




int rc(int num)
{
if(num == 1)
return 1;

return(2*rc(num-1));
}