Method fftBitReversal

src/main/java/com/thealgorithms/maths/FFT.java:232–241

(int n, int log2n, ArrayList<Complex> x)

    /* Swap the values of the signal with bit-reversal method */
    public static ArrayList<Complex> fftBitReversal(int n, int log2n, ArrayList<Complex> x) {
        int reverse;
        for (int i = 0; i < n; i++) {
            reverse = reverseBits(i, log2n);
            if (i < reverse) {
                Collections.swap(x, i, reverse);
            }
        }
        return x;
    }

    /* Divide by n if we want the inverse FFT */
    public static ArrayList<Complex> inverseFFT(int n, boolean inverse, ArrayList<Complex> x) {