思路:此题就是简单叉积运用,判断点在规则图形内,比如三角形,平行四边形等。
// #pragma comment(linker, "/STACK:1024000000,1024000000") #include <iostream> #include <algorithm> #include <iomanip> #include <sstream> #include <string> #include <stack> #include <queue> #include <deque> #include <vector> #include <map> #include <set> #include <cstdio> #include <cstring> #include <cmath> #include <cstdlib> #include <climits> using namespace std; // #define DEBUG #ifdef DEBUG #define debug(...) printf( __VA_ARGS__ ) #else #define debug(...) #endif #define CLR(x) memset(x, 0,sizeof x) #define MEM(x,y) memset(x, y,sizeof x) #define pk push_back template<class T> inline T Get_Max(const T&a,const T&b){return a < b?b:a;} template<class T> inline T Get_Min(const T&a,const T&b){return a < b?a:b;} // typedef long long LL; typedef unsigned long long ULL; typedef pair<int,int> ii; const double eps = 1e-10; const int inf = 1 << 30; const int INF = 0x3f3f3f3f; const int MOD = 1e9 + 7; struct Point{ double x, y; Point(){} Point(double _x, double _y){ x = _x; y = _y; } Point operator + (const Point& rhs)const{ return Point(x + rhs.x, y + rhs.y); } Point operator - (const Point& rhs)const{ return Point(x - rhs.x, y - rhs.y); } double operator ^ (const Point& rhs)const{ return (x * rhs.y - y * rhs.x); } double operator * (const Point& rhs)const{ return (x * rhs.x + y * rhs.y); } Point operator * (const double Num)const{ return Point(x * Num,y * Num); } friend ostream& operator << (ostream& output,const Point& rhs){ output << "(" << rhs.x << "," << rhs.y << ")"; return output; } }; typedef Point Vector; /*向量的模*/ inline double Length(const Vector& A){//Get the length of vector A; return sqrt(A * A);//sqrt(x*x+y*y); } /*向量夹角*/ inline double Angle(const Vector& A,const Point& B){ return acos(A * B/Length(A)/Length(B)); } /*向量A旋转rad弧度*/ inline Point Rotate(const Vector& A, double rad){ return Vector(A.x*cos(rad) - A.y*sin(rad),A.x*sin(rad) + A.y*cos(rad)); } Point LL,LU,RU,RL; double S; bool check(Point O){ double x = O^RL; double s1 = fabs((O - LL)^(RL - O)) / 2.0; double s2 = fabs((RL - O)^(RU - O)) / 2.0; double s3 = fabs((RU - O)^(LU - O)) / 2.0; double s4 = fabs((LU - O)^(LL - O)) / 2.0; if (s1 < eps || s2 < eps || s3 < eps || s4 < eps) return false; return (s1 + s2 + s3 + s4 <= S + eps); } int main() { // ios::sync_with_stdio(false); // freopen("in.txt","r",stdin); // freopen("out.txt","w",stdout); int t, icase = 0, n; cin >> t; while(t--){ cin >> LL.x >> LL.y >> RU.x >> RU.y; LU = Point(LL.x, RU.y); RL = Point(RU.x, LL.y); S = (RU.x - LL.x) * (RU.y - LL.y); cin >> n; int ans = 0; printf("Case %d:\n", ++icase); while(n--){ double x, y; cin >> x >> y; if (check(Point(x,y))) puts("Yes"); else puts("No"); } } return 0; }