Fast Fourier Transform, Algorithms, Pattern Matching, Convolution, Combination Sum.
multiplication, the coefficients must be integers. The coefficients without rounding off can have errors in the range of 10^-10 to 10^-15, and when we multiply these errors with power of 10s in the last step, if the power is greater than say 15 i.e. c[15]*10¹⁵ then these errors can contribute