计算多项式给定点x处的值

2019-02-03 381 阅读1分钟

$f(x)=a_{0}+a_{1}x+...+a_{n-1}x^{n-1}+a_{n}x^{n}$

const func = (n, a = [], x) => {
  let sum = a[0];
  for (let i = 1; i < n; i++) {
    sum += a[i] * x ** i;
  }
  return sum;
};

$f(x)=a_{0}+x(a_{1}+x(...(a_{n-1}+x(a_{x}))...))$

const func = (n,a=[],x)=>{
  let sum = a[n]
  for (let i = n;i>0;i--){
    sum = a[i-1]+ x*sum
  }
  return sum
}