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back to boardPlease help me Who can tell me what is wrong? // Geometry.cpp : Defines the entry point for the console application. // #include "stdafx.h" #include <vector> #include <list> #include <map> #include <set> #include <deque> #include <stack> #include <queue> #include <bitset> #include <algorithm> #include <functional> #include <numeric> #include <utility> #include <sstream> #include <iostream> #include <iomanip> #include <cstdio> #include <cmath> #include <cstdlib> #include <cctype> #include <string> #include <cstring> #include <ctime> using namespace std; #define sz(a) (a.size()) #define all(a) (a.begin(),a.end()) #define Sort(a) (sort(all(a))) #define pb (push_back) #define dump(x) cerr<<#x<<" = "<<(x)<<endl; #define debug(x) cerr<<#x<<" = "<<(x)<<" (L"<< __LINE__ <<")"<<" "<< __FILE__ <<endl; #define eps 1e-7 int sign (double x) { return ((x)>eps?1:((x)<-eps?2:0));} const double PI=acos(-1.0); const int INF=2100000000; struct point { double x; double y; }; struct line { point a; point b; }; double mult(point p1,point p2,point p0){ return (p1.x-p0.x)*(p2.y-p0.y)-(p2.x-p0.x)*(p1.y-p0.y); } double sqrdist(point a,point b){ return ((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y)); } int is_convex(int n,point *p){ int i,s[3]={1,1,1}; for(i=0;i<n && s[1]|s[2];i++){ double x=(mult(p[(i+1)%n],p[(i+2)%n],p[i])); s[sign(x)]=0; } return s[1]|s[2]; } bool dist(int n,point *p){ double dis=sqrdist(p[0],p[1]); int i; for(i=0;i<n;i++){ if(fabs(dis-sqrdist(p[i],p[(i+1)%n]))>=eps){ return (false); } } return (true); } double distance1(point a,point b){ return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y)); } double getangle(point a,point b,point c){ double sq=((a.x-b.x)*(a.y-c.y)-(a.x-c.x)*(a.y-b.y)); double ab=distance1(a,b); double bc=distance1(b,c); double sinphi=(ab*bc)/sq; return asin(sinphi); } bool isangles(int n,point *p){ double sinphi=getangle(p[0],p[1],p[2]); int i; for(i=0;i<n;i++){ if(fabs(sinphi-getangle(p[i],p[(i+1)%n],p[(i+2)%n]))>eps){ return (false); } } return (true); } bool isRight(int n,point *p){ if(dist(n,p) && is_convex(n,p) && isangles(n,p)){ return (true); } return (false); } int main(){ int n; int i; cin>>n; point *p=new point [n]; for(i=0;i<n;i++){ cin>>p[i].x; cin>>p[i].y; } (isRight(n,p))?(puts("YES")):(puts("NO")); return (0); } |
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