团体程序设计天梯赛 L2-018 多项式A除以B (25分)

题目链接：

L2-018 多项式A除以B (25分)

思路：

仿照竖式除法，维护余数和结果即可；

代码：

#include<bits/stdc++.h>

using namespace std;

inline void read(vector<double> & v) {
	int n;
	cin >> n;
	for(int i = 0; i < n; i++) {
		int e, c;
		cin >> e >> c;
		if(i == 0) v.resize(e + 1);
		v[e] = c;
	}
}
inline void out(vector<double> & v) {
	int ans = 0;
	for(double & x : v) if(abs(x) >= 0.1) ++ans;
	cout << ans;
	for(int i = v.size() - 1; i >= 0; i--) {
		if(abs(v[i]) >= 0.1) printf(" %d %.1f", i, v[i]);
		else if(!ans && !i)	cout << " 0 0.0";
	}
	cout << '\n';
}

int main() {
#ifdef MyTest
	freopen("Sakura.txt", "r", stdin);
#endif
	vector<double> a, b;
	read(a), read(b); 
	int n = a.size(), m = b.size();
	vector<double> ans(n);
	while(n >= m) {
		int e = n - m;
		double c = a[n - 1] * 1.0 / b[m - 1];
		ans[e] += c;
		vector<double> res(n);
		for(int i = 0; i < m; i++) res[i + e] = b[i] * c;
		for(int i = 0; i < n; i++) a[i] -= res[i];
		while(a[n - 1] == 0) --n;	
	}
	out(ans);
	out(a);
	return 0;
}