import { removeLeadingZeros } from "./remove-leading-zeros.js";


/** 
 * Returns the result of multiplies a polynomial by a constant in double 
 * precision.
 * 
 * @param c a constant
 * @param p a polynomial with coefficients given densely as an array of double
 * floating point numbers from highest to lowest power, e.g. `[5,-3,0]` 
 * represents the polynomial `5x^2 - 3x`
 * 
 * @example
 * ```typescript 
 * multiplyByConst(0.25, [3,2,1]); //=> [0.75, 0.5, 0.25]
 * ```
 * 
 * @doc
 */
function multiplyByConst(
        c: number,
        p: number[]): number[] {

    if (c === 0) { return []; }
    
    const d = p.length;
    const p_ = new Array<number>(d);
    for (let i=0; i<d; i++) {
        p_[i] = c*p[i];
    }
    
    // We *have* to clip due to possible floating point underflow
    return removeLeadingZeros(p_);
}


export  { multiplyByConst }