# ZeroJudge - f332: 貝瑞的鐵線體積
### 題目連結：https://zerojudge.tw/ShowProblem?problemid=f332
###### tags: `ZeroJudge` `數學` `微積分` `代數`

#include <iostream>
#include <iomanip>
using namespace std;
#define PI 3.14159265358979

struct polynomial {
	int power;
	double coefficients[15];

	void Square() {
		double buffer[15] = {};
		for (int i = 0; i <= power; ++i)
			for (int j = 0; j <= power; ++j)
				buffer[i + j] += coefficients[i] * coefficients[j];
		power <<= 1;
		for (int i = 0; i <= power; ++i)
			coefficients[i] = buffer[i];
	}

	double Sample(int value) {
		double mapped = 0, base = 1;
		for (int i = 0; i <= this->power; ++i, base *= value)
			mapped += this->coefficients[i] * base;
		return mapped;
	}

	double Revolution(int upper, int lower) {
		this->Square();
		for (int i = this->power; i >= 0; --i)
			this->coefficients[i + 1] = this->coefficients[i] / (i + 1);
		++(this->power);
		return (this->Sample(upper) - this->Sample(lower)) * PI;
	}

} wire;

int main() {
	cin.sync_with_stdio(false); cin.tie(nullptr);
	int times, upper, lower;
	cin >> times;
	while (times--) {
		cin >> wire.power;
		for (int i = wire.power; i >= 0; --i)
			cin >> wire.coefficients[i];
		cin >> lower >> upper;
		cout << fixed << setprecision(2) << wire.Revolution(upper, lower) << '\n';
	}
}