Hag is a very talented person. He has always had an artist inside him but his father forced him to study mechanical engineering.
Yesterday he spent all of his time cutting a giant piece of wood trying to make it look like a goose. Anyway, his dad found out that he was doing arts rather than studying mechanics and other boring subjects. He confronted Hag with the fact that he is a spoiled son that does not care about his future, and if he continues to do arts he will cut his 25 Lira monthly allowance.
Hag is trying to prove to his dad that the wooden piece is a project for mechanics subject. He also told his dad that the wooden piece is a strictly convex polygon with nn vertices.
Hag brought two pins and pinned the polygon with them in the 11-st and 22-nd vertices to the wall. His dad has qq queries to Hag of two types.
- 11 ff tt: pull a pin from the vertex ff, wait for the wooden polygon to rotate under the gravity force (if it will rotate) and stabilize. And then put the pin in vertex tt.
- 22 vv: answer what are the coordinates of the vertex vv.
Please help Hag to answer his father's queries.
You can assume that the wood that forms the polygon has uniform density and the polygon has a positive thickness, same in all points. After every query of the 1-st type Hag's dad tries to move the polygon a bit and watches it stabilize again.
The first line contains two integers nn and qq (3≤n≤100003≤n≤10000, 1≤q≤2000001≤q≤200000) — the number of vertices in the polygon and the number of queries.
The next nn lines describe the wooden polygon, the ii-th line contains two integers xixi and yiyi (|xi|,|yi|≤108|xi|,|yi|≤108) — the coordinates of the ii-th vertex of the polygon. It is guaranteed that polygon is strictly convex and the vertices are given in the counter-clockwise order and all vertices are distinct.
The next qq lines describe the queries, one per line. Each query starts with its type 11 or 22. Each query of the first type continues with two integers ff and tt (1≤f,t≤n1≤f,t≤n) — the vertex the pin is taken from, and the vertex the pin is put to and the polygon finishes rotating. It is guaranteed that the vertex ff contains a pin. Each query of the second type continues with a single integer vv (1≤v≤n1≤v≤n) — the vertex the coordinates of which Hag should tell his father.
It is guaranteed that there is at least one query of the second type.
The output should contain the answer to each query of second type — two numbers in a separate line. Your answer is considered correct, if its absolute or relative error does not exceed 10−410−4.
Formally, let your answer be aa, and the jury's answer be bb. Your answer is considered correct if |a−b|max(1,|b|)≤10−4|a−b|max(1,|b|)≤10−4
3 4
0 0
2 0
2 2
1 1 2
2 1
2 2
2 3
3.4142135624 -1.4142135624
2.0000000000 0.0000000000
0.5857864376 -1.4142135624
3 2
-1 1
0 0
1 1
1 1 2
2 1
1.0000000000 -1.0000000000
In the first test note the initial and the final state of the wooden polygon.
Red Triangle is the initial state and the green one is the triangle after rotation around (2,0)(2,0).
In the second sample note that the polygon rotates 180180 degrees counter-clockwise or clockwise direction (it does not matter), because Hag's father makes sure that the polygon is stable and his son does not trick him.
思路:每个顶点相对顶点、重心的距离、顶点重心当前点构成的角都可以预处理出来。每次旋转你只需维护重心的位置和第一个顶点的位置,每次查询都可以通过第一个点、重心位置以及预处理的信息O(1)得到某个点的位置。
我用double精度不够,换成long double过的。
1 #include <iostream> 2 #include <fstream> 3 #include <sstream> 4 #include <cstdlib> 5 #include <cstdio> 6 #include <cmath> 7 #include <string> 8 #include <cstring> 9 #include <algorithm> 10 #include <queue> 11 #include <stack> 12 #include <vector> 13 #include <set> 14 #include <map> 15 #include <list> 16 #include <iomanip> 17 #include <cctype> 18 #include <cassert> 19 #include <bitset> 20 #include <ctime> 21 22 using namespace std; 23 24 #define pau system("pause") 25 #define ll long long 26 #define pii pair<int, int> 27 #define pb push_back 28 #define mp make_pair 29 #define clr(a, x) memset(a, x, sizeof(a)) 30 31 const long double pi = acos(-1.0); 32 const int INF = 0x3f3f3f3f; 33 const int MOD = 1e9 + 7; 34 const long double EPS = 1e-9; 35 36 /* 37 #include <ext/pb_ds/assoc_container.hpp> 38 #include <ext/pb_ds/tree_policy.hpp> 39 40 using namespace __gnu_pbds; 41 tree<pli, null_type, greater<pli>, rb_tree_tag, tree_order_statistics_node_update> T; 42 */ 43 44 int n, q; 45 struct point { 46 long double x, y; 47 point() {} 48 point (long double x, long double y) : x(x), y(y) {} 49 void input() { 50 //scanf("%lf%lf", &x, &y); 51 cin >> x >> y; 52 } 53 void output() { 54 double tx = x, ty = y; 55 printf("%.12f %.12f ", tx, ty); 56 } 57 point operator - (const point &p) const { 58 return point(x - p.x, y - p.y); 59 } 60 point operator + (const point &p) const { 61 return point(x + p.x, y + p.y); 62 } 63 long double operator ^ (const point &p) const { 64 return x * p.y - y * p.x; 65 } 66 point operator / (const long double &k) const { 67 return point(x / k, y / k); 68 } 69 point operator * (const long double &k) const { 70 return point(x * k, y * k); 71 } 72 long double dis(const point &p) const { 73 return sqrt((x - p.x) * (x - p.x) + (y - p.y) * (y - p.y)); 74 } 75 } p[100015]; 76 long double d0[100015], d1[100015], th[100015]; 77 long double cal_th(point p1, point p0, point p2) { 78 long double th1 = atan2(p1.y - p0.y, p1.x - p0.x); 79 long double th2 = atan2(p2.y - p0.y, p2.x - p0.x); 80 long double res = th1 - th2; 81 if (res < 0) res += 2 * pi; 82 return res; 83 } 84 multiset<int> rem; 85 point get_pos(int index) { 86 long double th1 = atan2(p[1].y - p[0].y, p[1].x - p[0].x); 87 long double th2 = th1 - th[index]; 88 if (th2 < 0) th2 += 2 * pi; 89 return p[0] + point(d0[index] * cos(th2), d0[index] * sin(th2)); 90 } 91 void rot_and_update(int index2) { 92 point p2 = get_pos(index2); 93 long double th01 = atan2(p[0].y - p2.y, p[0].x - p2.x); 94 long double th02 = 3 * pi / 2; 95 long double th0 = th02 - th01; 96 if (th0 < 0) th0 += 2 * pi; 97 long double th11 = atan2(p[1].y - p2.y, p[1].x - p2.x); 98 //p[0].output(), p[1].output(), p2.output(); 99 long double th12 = th11 + th0; 100 if (2 * pi <= th12) th12 -= 2 * pi; 101 //printf("index2 = %d ", index2); 102 p[0] = point(p2.x, p2.y - d0[index2]); 103 p[1] = p2 + point(d1[index2] * cos(th12), d1[index2] * sin(th12)); 104 } 105 void get_wp() { 106 long double s = 0; 107 p[0] = point(0, 0); 108 for (int i = 2; i < n; ++i) { 109 long double ts = (p[i] - p[1]) ^ (p[i] - p[i + 1]); 110 p[0] = p[0] + (p[1] + p[i] + p[i + 1]) / 3 * ts; 111 s += ts; 112 } 113 p[0] = p[0] / s; 114 } 115 int main() { 116 scanf("%d%d", &n, &q); 117 p[0] = point(0, 0); 118 for (int i = 1; i <= n; ++i) { 119 p[i].input(); 120 } 121 get_wp(); 122 for (int i = 1; i <= n; ++i) { 123 th[i] = cal_th(p[1], p[0], p[i]); 124 d0[i] = p[0].dis(p[i]); 125 d1[i] = p[1].dis(p[i]); 126 } 127 rem.insert(1), rem.insert(2); 128 while (q--) { 129 int op; 130 scanf("%d", &op); 131 if (1 == op) { 132 int f, t; 133 scanf("%d%d", &f, &t); 134 multiset<int>::iterator it = rem.lower_bound(f); 135 rem.erase(it); 136 int v = *rem.begin(); 137 rot_and_update(v); 138 rem.insert(t); 139 } else { 140 int v; 141 scanf("%d", &v); 142 get_pos(v).output(); 143 } 144 } 145 return 0; 146 } 147 /* 148 10 10 149 0 -100000000 150 1 -100000000 151 1566 -99999999 152 2088 -99999997 153 2610 -99999994 154 3132 -99999990 155 3654 -99999985 156 4176 -99999979 157 4698 -99999972 158 5220 -99999964 159 1 2 5 160 2 1 161 1 1 7 162 2 5 163 1 5 4 164 1 4 2 165 2 8 166 1 7 9 167 2 1 168 1 2 10 169 */