注册公司网站如何注册,池州市建设工程质量安全监督局网站,网络营销有哪些例子,天元建设集团有限公司第十一建筑公司K - Triangle 计蒜客 - 42405
题意#xff1a;
给你一个三角形的三点#xff0c;再给你三角形边上一个点#xff0c;让你求另一个点(也要在三角形上)#xff0c;使得平分三角形的面积
题解:
计算几何 三角形的三边ab#xff0c;ac#xff0c;bc 如果点p在ab上#x…K - Triangle 计蒜客 - 42405
题意
给你一个三角形的三点再给你三角形边上一个点让你求另一个点(也要在三角形上)使得平分三角形的面积
题解:
计算几何 三角形的三边abacbc 如果点p在ab上离a点更近的话另一个点在bc上反之在ac上如果在bc上就开始二分bc上的点二分个1000来遍差不多就能得到另一个点 计算几何要求熟练使用模板整个代码基本上都是模板就看你会不会用 在计算几何这方面我还需要多练练
代码
#include cstdio
#include vector
#include queue
#include cstring
#include cmath
#include map
#include set
#include string
#include iostream
#include algorithm
#include iomanip
using namespace std;
#define sd(n) scanf(%d,n)
#define sdd(n,m) scanf(%d%d,n,m)
#define sddd(n,m,k) scanf(%d%d%d,n,m,k)
#define pd(n) printf(%d\n, n)
#define pc(n) printf(%c, n)
#define pdd(n,m) printf(%d %d, n, m)
#define pld(n) printf(%lld\n, n)
#define pldd(n,m) printf(%lld %lld\n, n, m)
#define sld(n) scanf(%lld,n)
#define sldd(n,m) scanf(%lld%lld,n,m)
#define slddd(n,m,k) scanf(%lld%lld%lld,n,m,k)
#define sf(n) scanf(%lf,n)
#define sc(n) scanf(%c,n)
#define sff(n,m) scanf(%lf%lf,n,m)
#define sfff(n,m,k) scanf(%lf%lf%lf,n,m,k)
#define ss(str) scanf(%s,str)
#define rep(i,a,n) for(int ia;in;i)
#define per(i,a,n) for(int in;ia;i--)
#define mem(a,n) memset(a, n, sizeof(a))
#define debug(x) cout #x : x endl
#define pb push_back
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define mod(x) ((x)%MOD)
#define gcd(a,b) __gcd(a,b)
#define lowbit(x) (x-x)
#define pii mapint,int
#define mk make_pair
#define rtl rt1
#define rtr rt1|1typedef pairint,int PII;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
const int MOD 1e9 7;
//const double eps 1e-9;
const ll INF 0x3f3f3f3f3f3f3f3fll;
//const int inf 0x3f3f3f3f;
inline int read()
{int ret 0, sgn 1;char ch getchar();while(ch 0 || ch 9){if(ch -)sgn -1;ch getchar();}while (ch 0 ch 9){ret ret*10 ch - 0;ch getchar();}return ret*sgn;
}
inline void Out(int a)
{if(a9) Out(a/10);putchar(a%100);
}
int qpow(int m, int k, int mod)
{int res 1, t m;while (k){if (k1)res res * t % mod;t t * t % mod;k 1;}return res;
}
ll gcd(ll a,ll b){return b0?a : gcd(b,a%b);}
ll lcm(ll a,ll b){return a*b/gcd(a,b);}
ll inv(ll x,ll m){return qpow(x,m-2,m)%m;}const int N 5e510;
int n,m;
typedef double db;
const db eps 1e-8;
const db inf 1e20;
const db pi acos(-1.0);int sgn(db x){if(fabs(x) eps)return 0;if(x 0)return -1;else return 1;
}struct Point{db x, y;Point(){}Point(db _x, db _y){x _x;y _y;}void input(){scanf(%lf%lf, x, y);}bool operator (Point b)const{return sgn(x-b.x) 0 sgn(y-b.y) 0;}Point operator -(const Point b)const{return Point(x-b.x, y-b.y);}//叉积db operator ^(const Point b)const{return x*b.y - y*b.x;}//点积db operator *(const Point b)const{return x*b.x y*b.y;}//返回两点的距离db dis(Point p){return hypot(x-p.x, y-p.y);}Point operator (const Point b)const{return Point(xb.x, yb.y);}Point operator *(const db k)const{return Point(x*k, y*k);}Point operator /(const db k)const{return Point(x/k, y/k);}
};struct Line{Point s,e;Line(){}Line(Point _s,Point _e){s _s;e _e;}// 点在线段上的判断bool pointonseg(Point p){return sgn((p-s)^(e-s)) 0 sgn((p-s) * (p-e)) 0;}// 求两直线的交点Point crosspoint(Line v){double a1 (v.e-v.s)^(s-v.s);double a2 (v.e-v.s)^(e-v.s);return Point((s.x*a2-e.x*a1)/(a2-a1),(s.y*a2-e.y*a1)/(a2-a1));}
};// 求点a和点b的中点
Point get_mid(Point a, Point b) {return (a b) * 0.5;
}// 根据三个点计算三角形面积
double area(Point a,Point b,Point c)
{return fabs((b - a) ^ (c - a) * 0.5);
}signed main()
{int t 1;Point a,b,c,p;Line ab,ac,bc;sd(t);while(t--){a.input(),b.input(),c.input(),p.input();ab Line(a,b),ac Line(a,c),bc Line(b,c);db s2 area(a,b,c)/2;if(!ab.pointonseg(p) !ac.pointonseg(p) !bc.pointonseg(p)){cout-1endl;continue;}if(ab.pointonseg(p))//如果p在ab上 {// 离a点更近 那么另一点在bc上 反之在ac上。if(a.dis(p) b.dis(p))//说明另一点在bc上 {Point l b,r c;Point mid get_mid(l,r);int time 1000;while(time--){mid get_mid(l,r);db s area(mid,p,b);int flag sgn(s-s2);//判断s和s2的面积 if(flag 0)break;if(flag 1)//ss2当S的面积更大此时要缩小面积说明终点在左侧 r mid;elsel mid;//ss2}printf(%.10lf %.10lf\n,mid.x,mid.y);}else//另一个点在ac上 {Point l a,r c;Point mid get_mid(l,r);int time 1000;while(time--){mid get_mid(l,r);db s area(mid,p,a);int flag sgn(s-s2);if(flag 0)break;if(flag 1)r mid;elsel mid;}printf(%.10lf %.10lf\n,mid.x,mid.y);}}else if(ac.pointonseg(p)){if(a.dis(p) c.dis(p)){Point l c,r b;Point mid get_mid(l,r);int time 1000;while(time--){mid get_mid(l,r);db s area(mid,p,c);int flag sgn(s-s2);if(flag 0)break;if(flag 1)r mid;elsel mid;}printf(%.10lf %.10lf\n,mid.x,mid.y);}else{Point l a,r b;Point mid get_mid(l,r);int time 1000;while(time--){mid get_mid(l,r);db s area(mid,p,a);int flag sgn(s-s2);if(flag 0)break;if(flag 1)r mid;elsel mid;}printf(%.10lf %.10lf\n,mid.x,mid.y);}}else{if(b.dis(p) c.dis(p)){Point l c,r a;Point mid get_mid(l,r);int time 1000;while(time--){mid get_mid(l,r);db s area(mid,p,c);int flag sgn(s-s2);if(flag 0)break;if(flag 1)r mid;elsel mid;}printf(%.10lf %.10lf\n,mid.x,mid.y);}else{Point l b,r a;Point mid get_mid(l,r);int time 1000;while(time--){mid get_mid(l,r);db s area(mid,p,b);int flag sgn(s-s2);if(flag 0)break;if(flag 1)r mid;elsel mid;}printf(%.10lf %.10lf\n,mid.x,mid.y);}}}return 0;
}
