bupt summer training for 16 #2 ——计算几何

https://vjudge.net/contest/171368#overview

 

A.一个签到题,用叉积来判断一个点在一条线的哪个方向

可以二分,数据范围允许暴力

 1 #include <cstdio>
 2 
 3 struct point {
 4     int x, y;
 5 }a[5010];
 6 
 7 int n, m, x[2], y[2], c[5010];
 8 
 9 int _cross(const point &A, const point &B) {
10     return A.x * B.y - A.y * B.x;
11 }
12 
13 int main() {
14     while(scanf("%d %d %d %d %d %d", &n, &m, &x[0], &y[0], &x[1], &y[1]) != EOF) {
15         if(n == 0) break;
16         c[0] = 0;
17         for(int i = 1;i <= n;i ++)
18             scanf("%d %d", &a[i].x, &a[i].y), c[i] = 0;
19         for(int X, Y, l, r, mid, ans, i = 1;i <= m;i ++) {
20             scanf("%d %d", &X, &Y);
21             if(_cross((point){a[1].x - a[1].y, y[0] - y[1]}, (point){X - a[1].y, Y - y[1]}) > 0) c[0] ++;
22             else {
23                 l = 1, r = n;
24                 while(l <= r) {
25                     mid = (l + r) >> 1;
26                     if(_cross((point){a[mid].x - a[mid].y, y[0] - y[1]}, (point){X - a[mid].y, Y - y[1]}) < 0) ans = mid, l = mid + 1;
27                     else r = mid - 1;
28                 }
29                 c[ans] ++;
30             }
31         }
32         for(int i = 0;i <= n;i ++)
33             printf("%d: %d\n", i, c[i]);
34         puts("");
35     }
36 }
View Code

 

B.横边和竖边都与对角线等价,很容易猜到最终的最优路线有等价变形

我们把所有边都等价为斜边,就会得到一个矩形

矩形四条边的斜率绝对值都为1

纵截距可以比较得到

可以发现我们要求的所谓周长

其实等价于最左边点和最右边点的横坐标之差

(或者最上边点与最下面点的纵坐标之差,这俩是相等的)

两个点的横坐标可以用直线联立得到

需要向外拓宽,+4即可

于是就得到了一个很简单又很妙的解法

1 n = input()
2 a = b = c = d = -6666666
3 for i in range(n):
4     x, y = map(int, raw_input().split())
5     a = max(a, x + y)
6     b = max(b, x - y)
7     c = max(c, y - x)
8     d = max(d, - x - y)
9 print a + b + c + d + 4

还有一个没有发现等价的凸包做法

凸包做法作重要的就是如何处理向外拓展

有一个思路就是每个点都拆成上下左右4个点

对这 4*n 个点做凸包再求周长

重点就是点的坐标到1e6,叉积的话,要开long long啊朋友!

 1 #include <cstdio>
 2 #include <algorithm>
 3 
 4 using std::max;
 5 
 6 const int maxn = 400010;
 7 
 8 typedef long long ll;
 9 
10 struct point {
11     ll x, y;
12     bool operator < (const point &a) const {
13         if(x != a.x) return x < a.x;
14         return y < a.y;
15     }
16     point operator - (const point &a) const {
17         return (point){x - a.x, y - a.y};
18     }
19 }p[maxn], q[maxn];
20 
21 int abs(int x, int y) {
22     return x > y ? x - y : y - x;
23 }
24 
25 int dis(const point &a, const point &b) {
26     return max(abs(a.x - b.x), abs(a.y - b.y));
27 }
28 
29 ll _cross(const point &a, const point &b) {
30     return a.x * b.y - a.y * b.x;
31 }
32 
33 int n0, n, N;
34 
35 long long ans;
36 
37 int convexhull() {
38     int m = 0;
39     std::sort(p, p + n);
40     for(int i = 0;i < n;i ++) {
41         while(m > 1 && _cross(q[m - 1] - q[m - 2], p[i] - q[m - 2]) <= 0) m --;
42         q[m ++] = p[i];
43     }
44     for(int k = m, i = n - 2;i >= 0;i --) {
45         while(m > k && _cross(q[m - 1] - q[m - 2], p[i] - q[m - 2]) <= 0) m --;
46         q[m ++] = p[i];
47     }
48     return m - 1;
49 }
50 
51 int main() {
52     scanf("%d", &n0);
53     for(int x, y, i = 0;i < n0;i ++) {
54         scanf("%d %d", &x, &y);
55         p[n ++] = (point){x + 1, y};
56         p[n ++] = (point){x - 1, y};
57         p[n ++] = (point){x, y + 1};
58         p[n ++] = (point){x, y - 1};
59     }
60     N = convexhull(), q[N] = q[0];
61     for(int i = 1;i <= N;i ++) ans += dis(q[i], q[i - 1]);
62     printf("%lld", ans);
63     return 0;
64 }
View Code

 

C.非常没意思的签到题,水了发Java

发现大多OJ(cf除外)都会要求Java的public类名必须为Main

 1 import java.util.Scanner;
 2 
 3 public class Main {
 4     public static void main(String []args) {
 5         Scanner input = new Scanner(System.in);
 6         double c, a, i;
 7         String s;
 8         while(true) {
 9             c = input.nextDouble();
10             if(c == 0.0) break;
11             for(i = 1, a = 0;;i ++) {
12                 a += 1 / (i + 1);
13                 if(a >= c) {
14                     s = String.format("%.0f", i);
15                     System.out.println(s + " card(s)");
16                     break;
17                 }
18             }
19         }
20     }
21 }
View Code

 

D.反正就是枚举所有球算出能否接触

需要的时间最短的就是会碰到的那个

重点在于如何求出反射后的方向向量

求向量a关于向量b的对称向量a'的话

可以利用一个性质

假设c为a在b上的投影向量

那有a + a' = 2c

c = ab / b.length / b.length * b

原题OJ挂了评测结果未知,先把Java代码放上来

 1 import java.util.Scanner;
 2 
 3 public class D {
 4     static double sqr(double x) {
 5         return x * x;
 6     }
 7     static class point {
 8         double x, y, z;
 9         point() {
10             x = y = z = 0;
11         }
12         point(double x_, double y_, double z_) {
13             x = x_;
14             y = y_;
15             z = z_;
16         }
17         point(point a) {
18             x = a.x;
19             y = a.y;
20             z = a.z;
21         }
22     };
23     static class circle extends point{
24         double r;
25         circle() {
26             x = y = r = z = 0;
27         }
28     };
29     static double length(point a) {
30         return Math.sqrt(sqr(a.x) + sqr(a.y) + sqr(a.z));
31     }
32     public static void main(String []args) {
33         Scanner input = new Scanner(System.in);
34         int t, n = input.nextInt();
35         point s = new point();
36         point d = new point();
37         point tmp = new point(), nex = new point();
38         circle[] a = new circle[100];
39         for(int i = 1;i <= n;i ++) {
40             a[i] = new circle();
41             a[i].x = input.nextDouble();
42             a[i].y = input.nextDouble();
43             a[i].z = input.nextDouble();
44             a[i].r = input.nextDouble();
45         }
46         s.x = input.nextDouble();
47         s.y = input.nextDouble();
48         s.z = input.nextDouble();
49         d.x = input.nextDouble();
50         d.y = input.nextDouble();
51         d.z = input.nextDouble();
52         double A = sqr(d.x) + sqr(d.y) + sqr(d.z), B, C, test;
53         double x, x1, x2, dis;
54         int last = -1;
55         for(int k = 1;;k ++) {
56             if(k > 10) {
57                 System.out.println("etc.");
58                 break;
59             }
60             t = -1;
61             dis = 0.0;
62             for(int i = 1;i <= n;i ++) {
63                 if(i == last) continue;
64                 B = (d.x * (s.x - a[i].x) + d.y * (s.y - a[i].y) + d.z * (s.z - a[i].z)) * 2;
65                 C = sqr(s.x - a[i].x) + sqr(s.y - a[i].y) + sqr(s.z - a[i].z) - sqr(a[i].r);
66                 test = sqr(B) - A * C * 4;
67                 if(test < 0) continue;
68                 else {
69                     x1 = (Math.sqrt(test) - B) / (A * 2);
70                     x2 = (-Math.sqrt(test) - B) / (A * 2);
71                     if(x1 < 0 && x2 < 0) continue;
72                     else {
73                         if(x2 >= 0) x = x2;
74                         else x = x1;
75                         if(x < dis || t == -1) {
76                             t = i;
77                             dis = x;
78                             tmp = new point(s.x + d.x * x, s.y + d.y * x, s.z + d.z * x);
79                             point tmp1 = new point(tmp.x - d.x - a[i].x, tmp.y - d.y - a[i].y, tmp.z - d.z - a[i].z);
80                             point tmp2 = new point(tmp.x - a[i].x, tmp.y - a[i].y, tmp.z - a[i].z);
81                             double tmp3 = (tmp1.x * tmp2.x + tmp1.y * tmp2.y + tmp1.z * tmp2.z) / length(tmp2) / length(tmp2);
82                             nex = new point(tmp3 * tmp2.x * 2 - tmp1.x - tmp2.x, tmp3 * tmp2.y * 2 - tmp1.y - tmp2.y, tmp3 * tmp2.z * 2 - tmp1.z - tmp2.z);
83                         } 
84                     }
85                 }
86             }
87             if(t == -1) break;
88             System.out.printf("%d ", t);
89             last = t;
90             s = new point(tmp);
91             d = new point(nex);
92         }
93     }
94 }
View Code

 

E.这个题...数学方法无从下手

我们可以考虑二分...考虑二分的重点在于

先观察是否满足单调性再看能不能写出judge函数

因为单调性决定了能我们是否应该坚持考虑如何写judge

 

先确定其中一个圆的半径

再根据与两边和第一个圆相切求另外两圆半径

再判断两圆相切相离相交

单调性是显而易见的,第一个圆半径太大,另外两圆相离

太小则相交

 

精度正常比要求小数位高2-4位就差不多

二分左边界为0,右边界我开的是内切圆半径

(推得式子太长了,所以写的也又臭又长)

  1 import java.util.Scanner;
  2 
  3 public class E {
  4     static class point {
  5         double x, y;
  6         point() { 
  7             x = y = 0;
  8         }
  9         point(double x_, double y_) {
 10             x = x_;
 11             y = y_;
 12         }
 13     };
 14     static final double pi = Math.acos(-1.0);
 15     static final double eps = 1e-10;
 16     static point[] p = new point[3];
 17     static point dec(point a, point b) {
 18         return new point(a.x - b.x, a.y - b.y);
 19     }
 20     static point inc(point a, point b) {
 21         return new point(a.x + b.x, a.y + b.y);
 22     }
 23     static double dot(point a, point b) {
 24         return a.x * b.x + a.y * b.y;
 25     } 
 26     static double sqr(double x) {
 27         return  x * x;
 28     }
 29     static double length(point a) {
 30         return Math.sqrt(dot(a, a));
 31     }
 32     static point unitp(point a) {
 33         double len = length(a);
 34         return new point(a.x / len, a.y / len);
 35     }
 36     static double cross(point a, point b) {
 37         return a.x * b.y - a.y * b.x;
 38     }
 39     static double calc(double A, double B, double C) {
 40         double test = sqr(B) - A * C * 4;
 41         if(test < 0) return -1;
 42         test = Math.sqrt(test);
 43         double x1 = (- B + test) / (A * 2);
 44         double x2 = (- B - test) / (A * 2);
 45         if(x1 > 0) return x1;
 46         if(x2 > 0) return x2;
 47         return -1;
 48     }
 49     static void Solve(double l, double r) {
 50         double t1, t2, t3, r1, r2, r3, A, B, C, D, flag;
 51         point c1, c2, c3, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6;
 52         r1 = r2 = r3 = 0;
 53         c1 = new point();
 54         for(int tt = 1;tt <= 66;tt ++) {
 55             r1 = (l + r) / 2;
 56             flag = 0;
 57             tmp1 = unitp(dec(p[1], p[0]));
 58             tmp2 = unitp(dec(p[2], p[0]));
 59             tmp3 = inc(tmp1, tmp2);
 60             t3 = Math.acos(dot(tmp1, tmp2) / length(tmp1) / length(tmp2));
 61             t1 = r1 / (Math.sin(t3 / 2));
 62             t2 = length(tmp3);
 63             c1 = inc(p[0], new point(t1 / t2 * tmp3.x, t1 / t2 * tmp3.y));
 64             
 65             tmp1 = unitp(dec(p[0], p[1]));
 66             tmp2 = unitp(dec(p[2], p[1]));
 67             tmp3 = inc(tmp1, tmp2);
 68             tmp4 = dec(c1, p[1]);
 69             t3 = Math.acos(dot(tmp1, tmp2) / length(tmp1) / length(tmp2));
 70             t1 = Math.sin(t3 / 2);
 71             t2 = length(tmp3);
 72             A = sqr(t1 * t2) - sqr(t2);
 73             B = (t1 * t2 * r1 + dot(tmp3, tmp4)) * 2;
 74             C = sqr(r1) - dot(tmp4, tmp4); 
 75             D = calc(A, B, C);
 76             if(D == -1) flag = 1;
 77             c2 = inc(p[1], new point(D * tmp3.x, D * tmp3.y));
 78             r2 = t1 * length(new point(D * tmp3.x, D * tmp3.y));
 79             
 80             tmp1 = unitp(dec(p[0], p[2]));
 81             tmp2 = unitp(dec(p[1], p[2]));
 82             tmp3 = inc(tmp1, tmp2);
 83             tmp4 = dec(c1, p[2]);
 84             t3 = Math.acos(dot(tmp1, tmp2) / length(tmp1) / length(tmp2));
 85             t1 = Math.sin(t3 / 2);
 86             t2 = length(tmp3);
 87             A = sqr(t1 * t2) - sqr(t2);
 88             B = (t1 * t2 * r1 + dot(tmp3, tmp4)) * 2;
 89             C = sqr(r1) - dot(tmp4, tmp4); 
 90             D = calc(A, B, C);
 91             if(D == -1) flag = 1;
 92             c3 = inc(p[2], new point(D * tmp3.x, D * tmp3.y));
 93             r3 = t1 * length(new point(D * tmp3.x, D * tmp3.y));
 94             if(flag == 1 || sqr(c2.x - c3.x) + sqr(c2.y - c3.y) > sqr(r2 + r3)) r = r1 - eps;
 95             else l = r1 + eps;
 96         }
 97         System.out.printf("%.6f %.6f %.6f\n", r1, r2, r3);
 98     }
 99     public static void main(String []args) {
100         Scanner input = new Scanner(System.in);
101         for(int i = 0;i < 3;i ++) p[i] = new point();
102         while(true) {
103             for(int i = 0;i < 3;i ++) {
104                 p[i].x = input.nextDouble();
105                 p[i].y = input.nextDouble();
106             }
107             if(length(p[0]) == 0 && length(p[1]) == 0 && length(p[2]) == 0) break;
108             Solve(0, Math.abs(cross(dec(p[1], p[0]), dec(p[2], p[0]))) / (length(dec(p[1], p[0])) + length(dec(p[2], p[0])) + length(dec(p[1], p[2]))));
109         }    
110     }
111 }
View Code

维基上有公式,戳这里 

l里面是关于这个问题的历史...仍然没有给出推导或者证明...

所以代码去看别人的题解就好了,反正也记不住公式hhh

 

F.一个很裸的矩形周长并,现场只带了矩形面积并的板子

魔改了好久才改对成周长并的板子...所以重写了一发

重点是数据范围居然支持暴力啊淦!暴力艹正解啦,夭寿啦!

(理解的一个关键在与线段树的叶子节点也都是一个线段!)

 1 #include <cstdio>
 2 #include <algorithm>
 3 
 4 #define rep(i, j, k) for(int i = j;i <= k;i ++)
 5 
 6 using namespace std;
 7 
 8 const int maxn = 20010;
 9 
10 int n, k1, k2, tot1, tot2;
11 
12 int ans, a1[maxn], a2[maxn], sum[maxn], cnt[maxn];
13 
14 struct node {
15     int x, y, c, d;
16     bool operator < (const node &a) const {
17         return c < a.c;
18     }
19 }line1[maxn], line2[maxn];
20 
21 void modify1(int o, int l, int r, int s, int t, int k, int p) {
22     if(s <= l && r <= t) {
23         cnt[o] += k;
24         if(cnt[o]) ans += p * (a1[r + 1] - a1[l] - sum[o]), sum[o] = a1[r + 1] - a1[l];
25         else if(l == r) ans += p * (a1[r + 1] - a1[l]), sum[o] = 0;
26         else ans += p * (sum[o] - (sum[o << 1] + sum[o << 1 | 1])), sum[o] = sum[o << 1] + sum[o << 1 | 1];
27      }
28      else {
29          int mid = (l + r) >> 1;
30          if(cnt[o]) p = 0;
31          if(s <= mid) modify1(o << 1, l, mid, s, t, k, p);
32          if(t > mid) modify1(o << 1 | 1, mid + 1, r, s, t, k, p);
33          if(!cnt[o]) sum[o] = sum[o << 1] + sum[o << 1 | 1];
34      }
35 }
36 
37 void modify2(int o, int l, int r, int s, int t, int k, int p) {
38     if(s <= l && r <= t) {
39         cnt[o] += k;
40         if(cnt[o]) ans += p * (a2[r + 1] - a2[l] - sum[o]), sum[o] = a2[r + 1] - a2[l];
41         else if(l == r) ans += p * (a2[r + 1] - a2[l]), sum[o] = 0;
42         else ans += p * (sum[o] - (sum[o << 1] + sum[o << 1 | 1])), sum[o] = sum[o << 1] + sum[o << 1 | 1];
43      }
44      else {
45          int mid = (l + r) >> 1;
46          if(cnt[o]) p = 0;
47          if(s <= mid) modify2(o << 1, l, mid, s, t, k, p);
48          if(t > mid) modify2(o << 1 | 1, mid + 1, r, s, t, k, p);
49          if(!cnt[o]) sum[o] = sum[o << 1] + sum[o << 1 | 1];
50      }
51 }
52 
53 int main() {
54     k1 = k2 = 1;
55     int l, r, x[2], y[2];
56     scanf("%d", &n);
57     rep(i, 1, n) {
58         rep(j, 0, 1) scanf("%d %d", &x[j], &y[j]);
59         line1[++ tot1] = (node){x[0], x[1], y[0], 1}, a1[tot1] = x[0];
60         line1[++ tot1] = (node){x[0], x[1], y[1],-1}, a1[tot1] = x[1];
61         line2[++ tot2] = (node){y[0], y[1], x[0], 1}, a2[tot2] = y[0];
62         line2[++ tot2] = (node){y[0], y[1], x[1],-1}, a2[tot2] = y[1];
63     }
64     sort(line1 + 1, line1 + tot1 + 1), sort(a1 + 1, a1 + tot1 + 1);
65     sort(line2 + 1, line2 + tot2 + 1), sort(a2 + 1, a2 + tot2 + 1);
66     rep(i, 2, tot1) {
67         if(a1[i] != a1[k1])
68             a1[++ k1] = a1[i];
69         if(a2[i] != a2[k2])
70             a2[++ k2] = a2[i];
71     }
72     rep(i, 1, tot1) {
73         l = lower_bound(a1 + 1, a1 + k1 + 1, line1[i].x) - a1;
74         r = lower_bound(a1 + 1, a1 + k1 + 1, line1[i].y) - a1 - 1;
75         modify1(1, 1, k1 - 1, l, r, line1[i].d, 1);
76     }
77     rep(i, 1, tot2) {
78         l = lower_bound(a2 + 1, a2 + k2 + 1, line2[i].x) - a2;
79         r = lower_bound(a2 + 1, a2 + k2 + 1, line2[i].y) - a2 - 1;
80         modify2(1, 1, k2 - 1, l, r, line2[i].d, 1);
81     }
82     printf("%d", ans);
83     return 0;
84 }
View Code

 

 G.有多种图形,一个比较蠢的思路就是给每个图形造一个类...

但是思考一下,判断不同的图形相交,其实还是在判断边相交

所以都转换成判断线段相交就好了...

(附:如果使用scanf的格式化读入的话,一定要和读入的格式完全相同

因为用格式化读入的话,就不会忽略空格了...

  1 #include <cstdio>
  2 #include <vector>
  3 #include <iostream>
  4 #include <algorithm>
  5 
  6 using namespace std;
  7 
  8 #define pr pair<double, double>
  9 #define f(p) p.first
 10 #define s(p) p.second
 11 #define mp make_pair
 12 #define pb push_back
 13 
 14 struct node {
 15     string m;
 16     vector<pr> a;
 17     bool operator < (const node &a) const {
 18         return m < a.m;
 19     }
 20 };
 21 
 22 int n;
 23 
 24 char s[10];
 25 
 26 node tmp;
 27 
 28 pr temp[20];
 29 
 30 vector<node> h;
 31 
 32 vector<string> ans[30];
 33 
 34 double cross(pr p1, pr p2) {
 35     return f(p1) * s(p2) - f(p2) * s(p1);
 36 }
 37 
 38 bool line_cross(pr p1, pr p2, pr p3, pr p4) {
 39     double t1 = cross(mp(f(p2) - f(p1), s(p2) - s(p1)), mp(f(p3) - f(p1), s(p3) - s(p1)));
 40     double t2 = cross(mp(f(p2) - f(p1), s(p2) - s(p1)), mp(f(p4) - f(p1), s(p4) - s(p1)));
 41     double t3 = cross(mp(f(p4) - f(p3), s(p4) - s(p3)), mp(f(p1) - f(p3), s(p1) - s(p3)));
 42     double t4 = cross(mp(f(p4) - f(p3), s(p4) - s(p3)), mp(f(p2) - f(p3), s(p2) - s(p3)));
 43     if(!(1ll * t1 * t2 < 0 || ((t1 == 0 || t2 == 0) && (t1 + t2 != 0)))) return 0;
 44     if(!(1ll * t3 * t4 < 0 || ((t3 == 0 || t4 == 0) && (t3 + t4 != 0)))) return 0;
 45     return 1;
 46 }
 47 
 48 int main() {
 49     while(scanf("%s", s)) {
 50         if(s[0] == '.') return 0;
 51         if(s[0] == '-') {
 52             sort(h.begin(), h.end());
 53             for(int i = 0;i < h.size();i ++) {
 54                 ans[i].clear();
 55                 for(int j = 0;j < h.size();j ++) {
 56                     if(i == j) continue;
 57                     int x = 0;
 58                     for(int p = 1;p <  h[i].a.size();p ++) {
 59                         for(int q = 1;q < h[j].a.size();q ++) {
 60                             if(line_cross(h[i].a[p - 1], h[i].a[p], h[j].a[q - 1], h[j].a[q])) x = 1;
 61                             if(x) break;
 62                         }
 63                         if(x) break;
 64                     }
 65                     if(x) ans[i].pb(h[j].m);
 66                 }
 67                 switch(ans[i].size()) {
 68                     case 0:cout << h[i].m << " has no intersections" <<endl;
 69                         break;
 70                     case 1:cout << h[i].m << " intersects with " << ans[i][0] << endl;
 71                         break;
 72                     case 2:cout << h[i].m << " intersects with " << ans[i][0] <<  " and " << ans[i][1] <<endl;
 73                         break;
 74                     default:{
 75                         cout << h[i].m << " intersects with ";
 76                         for(int j = 0;j + 1 < ans[i].size();j ++)
 77                             cout << ans[i][j] << ", ";
 78                         cout << "and " << ans[i][ans[i].size() - 1] << endl;
 79                         break; 
 80                     }
 81                 }
 82             }
 83             h.clear();
 84             puts("");
 85         }
 86         else {
 87             tmp.a.clear();
 88             tmp.m = s;
 89             scanf("%s", s);
 90             switch(s[0]) {
 91                 case 'l':{
 92                     scanf(" (%lf,%lf)", &f(temp[0]), &s(temp[0]));
 93                     scanf(" (%lf,%lf)", &f(temp[1]), &s(temp[1]));
 94                     tmp.a.pb(temp[0]);
 95                     tmp.a.pb(temp[1]);
 96                     break;
 97                 }
 98                 case 't':{
 99                     scanf(" (%lf,%lf)", &f(temp[0]), &s(temp[0]));
100                     scanf(" (%lf,%lf)", &f(temp[1]), &s(temp[1]));
101                     scanf(" (%lf,%lf)", &f(temp[2]), &s(temp[2]));
102                     tmp.a.pb(temp[0]);
103                     tmp.a.pb(temp[1]);
104                     tmp.a.pb(temp[2]);
105                     break;
106                 }
107                 case 'p' :{
108                     cin >> n;
109                     for(int i = 0;i < n;i ++) {
110                         scanf(" (%lf,%lf)", &f(temp[i]), &s(temp[i]));
111                         tmp.a.pb(temp[i]);
112                     }
113                     break;
114                 }
115                 case 'r':{
116                     scanf(" (%lf,%lf)", &f(temp[0]), &s(temp[0]));
117                     scanf(" (%lf,%lf)", &f(temp[1]), &s(temp[1]));
118                     scanf(" (%lf,%lf)", &f(temp[2]), &s(temp[2]));
119                     tmp.a.pb(temp[0]);
120                     tmp.a.pb(temp[1]);
121                     tmp.a.pb(temp[2]);
122                     temp[3] = mp(f(temp[0]) + f(temp[2]) - f(temp[1]), s(temp[0]) + s(temp[2]) - s(temp[1]));
123                     tmp.a.pb(temp[3]);
124                     break;
125                 }
126                 case 's':{
127                     scanf(" (%lf,%lf)", &f(temp[0]), &s(temp[0]));
128                     scanf(" (%lf,%lf)", &f(temp[2]), &s(temp[2]));
129                     f(temp[4]) = (f(temp[0]) + f(temp[2])) / 2;
130                     s(temp[4]) = (s(temp[0]) + s(temp[2])) / 2;
131                     tmp.a.pb(temp[0]);
132                     tmp.a.pb(mp(f(temp[4]) - s(temp[2]) + s(temp[4]), s(temp[4]) + f(temp[2]) - f(temp[4])));
133                     tmp.a.pb(temp[2]);
134                     tmp.a.pb(mp(f(temp[4]) + s(temp[2]) - s(temp[4]), s(temp[4]) - f(temp[2]) + f(temp[4])));
135                     break;
136                 }
137             }
138             tmp.a.pb(tmp.a[0]);
139             h.pb(tmp);
140         }
141     }
142 }
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H.

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posted @ 2017-07-19 22:30  ztztyyy  阅读(151)  评论(0编辑  收藏  举报