a[20][20], b[20][20], c[20][20]: Matrices for multiplication. no_rows_a, no_cols_a, no_rows_b, no_cols_b, rows_c, cols_c: Dimensions of the matrices. file_a, file_b ...

The FFT multiplication method excels at efficiently multiplying large polynomials, becoming significantly faster than the direct method as polynomial degrees increase, despite its overhead for smaller ...