Rotate the Shell Part Template

Convex hull diameter

Detailed description of convex hull diameter

// Calculate the convex hull diameter. Input convex hull Ch. The number of vertices is N, which is arranged counterclockwise. The square of the output diameter

Int rotating_calipers (int n) {int q = 1; int ans = 0; ch [N] = CH [0]; for (INT I = 0; I <N; I ++) {While (MUL (CH [I + 1], CH [q + 1], CH [I])> MUL (CH [I + 1], ch [Q], CH [I]) // enumerate an edge of a convex hull and scan other points. Calculate the triangle area to find the farthest point Q = (q + 1) % N; ans = max (ANS, max (DIS (CH [I]-ch [Q]), DIS (CH [I + 1]-ch [q + 1]);} return ans ;}

Minimum distance between convex compartment

Struct point {Double X, Y; point (double x = 0, Double Y = 0): x (x), y (y) {} // constructor for easy coding} p [N], Q [N]; typedef point pointt; pointt operator + (point a, point B) {return point (. X + B. x,. Y + B. y);} pointt operator-(point a, point B) {return point (. x-b.x,. y-b.y);} int DCMP (Double X) {If (FABS (x) <EPS) return 0; else return x <0? -1:1;} bool operator = (const point & A, const point & B) {return DCMP (. x-b.x) = 0 & DCMP (. y-b.y) = 0;} double dot (point a, point B) {return. x * B. X +. y * B. y;} double DIS (point a) {return SQRT (dot (A, A);} double cross (point a, point B) {return. x * B. y-a.y * B. x;} void Anticlock (point P [], int N) // sort the {for (INT I = 0; I <N-2; I ++) {Double K = cross (P [I + 1]-P [0], p [I + 2]-P [0]); If (DCMP (k)> 0) return; else if (DCMP (k) <0) {reverse (p, p + n); Return ;}} double distoline (point a, point B, point C) // The shortest distance from the point to the line AB {If (DCMP (DIS (a-B) = 0) return DIS (a-c ); if (DCMP (dot (a-B, a-c) <0) return DIS (a-c); If (DCMP (dot (B-, b-c) <0) return DIS (B-c); Return FABS (Cross (a-B, a-c)/DIS (a-B );} double dist (point a, point B, point C, point D) // The shortest distance between line AB and Cd {double ans = distoline (A, B, C ); ans = min (ANS, distoline (A, B, D); ans = min (ANS, distoline (c, d, A); ans = min (ANS, distoline (c, d, B); Return ans;} double MUL (point a, point B, point C) {return cross (B-a, c-);} double solve (point P [], int N, point Q [], int m) {int I; int miny = 0, Maxy = 0; for (I = 0; I <n; I ++) {If (P [I]. Y <p [miny]. y) miny = I ;}for (I = 0; I <m; I ++) if (Q [I]. y> q [Maxy]. y) Maxy = I; double ans = DIS (P [miny]-Q [Maxy]); for (I = 0; I <n; I ++) {double TMP; while (TMP = MUL (P [miny], p [miny + 1], Q [Maxy + 1])-Mul (P [miny], p [miny + 1], Q [Maxy])> EPS) Maxy = (Maxy + 1) % m; If (DCMP (TMP)> 0) ans = min (ANS, distoline (P [miny], P [miny + 1], Q [Maxy]); else ans = min (ANS, dist (P [miny], p [miny + 1], Q [Maxy], Q [Maxy + 1]); // edge-edge miny = (miny + 1) % N;} return ans ;}