Fast Fourier Transform, Algorithms, Pattern Matching, Convolution, Combination Sum.
x in r_idft] return c def fft_multiply(p, q): sign = (p >= 0 and q >= 0) or (p < 0 and q < 0) p, q = abs(p), abs(q) p_coefficients = get_coefficients(p) q_coefficients = get_coefficients(q) c = get_multiplication_coefficients(p_coefficients, q_coefficients) h = 1 result = 0 for i in range(len(c)):