Ural 1258 镜面对称
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#include<cstdio> #include<cstring> #include<cmath> #include<iostream> #include<algorithm> #include<queue> using namespace std; const double eps = 1e-8; const double PI = acos(-1.0); const double INF = 1000000000000000.000; struct Point{ double x,y; Point(double x=0, double y=0) : x(x),y(y){ } //构造函数 }; typedef Point Vector; Vector operator + (Vector A , Vector B){return Vector(A.x+B.x,A.y+B.y);} Vector operator - (Vector A , Vector B){return Vector(A.x-B.x,A.y-B.y);} Vector operator * (double p,Vector A){return Vector(A.x*p,A.y*p);} Vector operator / (Vector A , double p){return Vector(A.x/p,A.y/p);} bool operator < (const Point& a,const Point& b){ return a.x < b.x ||( a.x == b.x && a.y < b.y); } int dcmp(double x){ if(fabs(x) < eps) return 0; else return x < 0 ? -1 : 1; } bool operator == (const Point& a, const Point& b){ return dcmp(a.x - b.x) == 0 && dcmp(a.y - b.y) == 0; } ///向量(x,y)的极角用atan2(y,x); inline double Dot(Vector A, Vector B){ return A.x*B.x + A.y*B.y; } inline double Length(Vector A) { return sqrt(Dot(A,A)); } inline double Angle(Vector A, Vector B) { return acos(Dot(A,B) / Length(A) / Length(B)); } double Cross(Vector A, Vector B) { return A.x*B.y - A.y * B.x; } Point read_point(){ Point A; scanf("%lf %lf",&A.x,&A.y); return A; } /*************************************分 割 线*****************************************/ int main() { //freopen("E:\\acm\\input.txt","r",stdin); double W,D; Point S,T; char s[1005]; scanf("%lf %lf",&W,&D); double x,y; scanf("%lf %lf",&x,&y); S = Point(-x,y); scanf("%lf %lf",&x,&y); T = Point(-x,y); scanf("%s",s); int len = strlen(s); for(int i=0;i<len;i++){ if(s[i] == 'F'){ S.y = -S.y; } else if(s[i] == 'L'){ S.x = -S.x; } else if(s[i] == 'B'){ S.y = 2*D -S.y; } if(s[i] == 'R'){ S.x = -2*W-S.x; } //cout<<S.x<<" "<<S.y<<endl; } double ans = Length(S-T); printf("%.4lf\n",ans); }