HDU 1392 Surround the Trees 构造凸包
摘要:
又是一道模板题#include #include #include #include #include #include #include using namespace std;struct P{ int x,y; double angle;} p[50010];bool cmp(P p1,P p2){ return p1.angle > p2.angle;}double calangle(P p,P t){ return ((t.x-p.x)*(t.x-p.x) + 1 - (t.x-p.x-1)*(t.x-p.x-1))/(2*sqrt((t.x-p.x)*(t.... 阅读全文