【2020春招记录】网易雷火笔试

又是为自己的无知流泪的一年

• 一. 网易雷火笔试 300’
  1. 第一题26个字母分别算个斐波那契就行
  2. 第二题是个小贪心，按价值从大到小排个序，从最大的开始杀，杀这个数最好的时间就是他消失之前的那个时间点。
  3. 第三题一个模拟，按题目要求模拟就行
  4. 第四题四元数坑了我，最后20分钟调出了样例交上去还是0分，这题我实在没法手出样例算了，有时间好好再学学四元数，再调吧，放一个没A的代码省的删了。

// Didn't AC 
#define _CRT_SECURE_NO_WARNINGS
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
using namespace std;

struct quaternion{
	double t;
	double x; 
	double y; 
	double z;
};

quaternion mul(quaternion left, quaternion right)
{
	quaternion ans;
	double d1, d2, d3, d4;

	d1 = left.t * right.t;
	d2 = -left.x * right.x;
	d3 = -left.y * right.y;
	d4 = -left.z * right.z;
	ans.t = d1 + d2 + d3 + d4;

	d1 = left.t * right.x;
	d2 = right.t * left.x;
	d3 = left.y * right.z;
	d4 = -left.z * right.y;
	ans.x = d1 + d2 + d3 + d4;

	d1 = left.t * right.y;
	d2 = right.t * left.y;
	d3 = left.z * right.x;
	d4 = -left.x * right.z;
	ans.y = d1 + d2 + d3 + d4;

	d1 = left.t * right.z;
	d2 = right.t * left.z;
	d3 = left.x * right.y;
	d4 = -left.y * right.x;
	ans.z = d1 + d2 + d3 + d4;

	return ans;
}

quaternion VtoQ(double PosX, double PosY, double PosZ)
{
	quaternion ans;

	ans.t = 0.0;
	ans.x = PosX;
	ans.y = PosY;
	ans.z = PosZ;

	return ans;
}

int n;
vector<int> ch[2001];
quaternion node[2001];
quaternion coor[2001];
int fa[2001],root;
double Tdata[2001][20][10];
int m[2001];


void rotate(int p, quaternion q) {
	quaternion qq;
	qq.x = -q.x;
	qq.y = -q.y;
	qq.z = -q.z;
	qq.t = q.t;

	for (auto it : ch[p]) {
		node[it] = mul(qq, node[it]);
		node[it] = mul(node[it],q);
		rotate(it, q);
	}
	return;
}

void getans(int p) {
	for (auto it : ch[p]) {
		coor[it].x = coor[p].x + node[it].x;
		coor[it].y = coor[p].y + node[it].y;
		coor[it].z = coor[p].z + node[it].z;
		coor[it].t = coor[p].t + node[it].t;
		getans(it);
	}
}

quaternion line(quaternion q0, quaternion q1,double s) {
	q0.t *= (1.0f-s);
	q0.x *= (1.0f-s);
	q0.y *= (1.0f-s);
	q0.z *= (1.0f-s);

	q1.t *= s;
	q1.x *= s;
	q1.y *= s;
	q1.z *= s;
	quaternion ans;
	ans.x = q0.x + q1.x;
	ans.y = q0.y + q1.y;
	ans.z = q0.z + q1.z;
	ans.t = q0.t + q1.t;

	double xx = ans.x * ans.x;
	double yy = ans.y * ans.y;
	double zz = ans.z * ans.z;
	double tt = ans.t * ans.t;

	double ss = sqrt(xx + yy + zz + tt);
	
	ans.t /= ss;
	ans.x /= ss;
	ans.y /= ss;
	ans.z /= ss;
	return ans;
}

int main() {
	scanf("%d", &n);
	for (int i = 0; i < n; i++) {
		int a;
		double x, y, z;
		cin >> a >> x >> y >> z;
		if (a != -1) ch[a].push_back(i);
		else root = i;
		fa[i] = a;
		node[i] = VtoQ(x, y, z);
	}
	for (int i = 0; i < n; i++) {
		 cin >> m[i];
		for (int j = 0; j < m[i]; j++) {
			for (int k = 0; k < 5; k++)
				cin >> Tdata[i][j][k];
		}
	}
	double T; cin >> T;
	for (int i = 0; i < n; i++) {
		double LastTime = 0;
		quaternion LastQ;
		for (int j = 0; j < m[i]; j++) {
			double time = Tdata[i][j][0];
			quaternion q = { Tdata[i][j][2], Tdata[i][j][3], Tdata[i][j][4], Tdata[i][j][1] };
			if (time <= T) {
				rotate(i, q);
			}
			else {
				quaternion temp = line(LastQ, q, (T - LastTime) / (time-LastTime));
				rotate(i, temp);
				break;
			}
			LastTime = time;
			LastQ = q;
		}
	}
	getans(root);
	for (int i = 0; i < n; i++) {
		printf("%.2lf %.2lf %.2lf\n", coor[i].x, coor[i].y, coor[i].z);
	}
	return 0;
}