凸多边形 HRBUST - 1429 计算几何_凸包_未调完
Code:
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <cmath>
#define setIO(s) freopen(s".in","r",stdin)
#define maxn 200000
const double eps = 0.000000000001;
using namespace std;
int n,m;
struct Point {
double x,y;
Point (double x = 0,double y = 0) : x(x),y(y){}
}point[maxn],ask[maxn];
int exis(double t) { return (fabs(t) <= eps) ? 0 : (t < 0 ? -1 : 1); }
double det(double x1,double y1,double x2,double y2) { return x1*y2-x2*y1; }
double cross(Point a,Point b,Point c) { return det(b.x-a.x,b.y-a.y,c.x-a.x,c.y-a.y); }
bool solve(){
memset(point,0,sizeof(point));
memset(ask,0,sizeof(ask));
for(int i = 1;i <= n; ++i) scanf("%lf%lf",&point[i].x,&point[i].y);
scanf("%d",&m);
for(int i = 1;i <= m; ++i) scanf("%lf%lf",&ask[i].x,&ask[i].y);
for(int i = 1;i <= m; ++i) {
int l = 2,r = n,ans = 0;
if(exis(cross(point[1],ask[i],point[2])) != 1 || exis(cross(point[1],ask[i],point[n])) != -1)
return false;
while(l <= r) {
int mid = (l + r) >> 1;
if(exis(cross(point[1],point[mid],ask[i])) == -1)
r = mid - 1;
else
ans = mid,l = mid + 1;
}
if(!(exis(cross(point[ans-1],point[ans],ask[i])) == -1)) return false;
}
return true;
}
int main(){
//setIO("input");
while(scanf("%d",&n)!=EOF)
{
if(solve())
printf("YES\n");
else
printf("NO\n");
}
return 0;
}
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