How to implement 3 nested for loops with variable length of recurrence

[mac.aditya98]

for(uint64_t i = 1; i <= log2(n); i++){

	m = pow(2,i);

	k_ = (p - 1)/m;
	a = modExp(r,k_,p);

	for(uint64_t j = 0; j < n; j+=m){

		for(uint64_t k = 0; k < m/2; k++){

			factor1 = result[j + k];
			factor2 = modulo(modExp(a,k,p)*result[j + k + m/2],p);
		
			result[j + k] 		= modulo(factor1 + factor2, p);
			result[j + k+m/2] 	= modulo(factor1 - factor2, p);

		}
	}

}