牛顿法求多项式的根

C++代码

#include <iostream>
#include <cstdio>

using namespace std;

const int maxn = 105;

int a[maxn];

int n, t;

int main()
{
	cin >> n >> t;
	for (int i = 0; i <= n; i++) cin >> a[i];

	cout << "原式：" ;
	for (int i = 0; i <= n; i++)
	{
		if (i) cout << " + ";
		cout << a[i] ;
		if (i != n) cout << "x^" << n-i;
		cout << " "; 
	}
	cout << endl;

	int r, s;

	r = a[0];
	a[0] = 0;

	for (int i = 1; i <= n + 1; i++)
	{
		s = a[i];
		a[i] = r;
		r = r * t + s;
	}

	//for (int i = 0; i < 5; i++) cout << a[i] << " ";
	//cout << endl;

	cout << "变形：" ;
	printf("(x - %d) * ", t);
	cout << "( ";
	for (int i = 1; i <= n; i++)
	{
		if (i != 1) cout << " + ";
		cout << a[i] ;
		if (i != n ) cout << "x^" << n - i;
	}
	cout << ") + " << a[n + 1] << endl;
	return 0;
}

 

测试数据

/*

2 4
1 2 -24

2 4
1 2 -25

3 2
1 -2 1 4

*/