CF 9B模拟

从(0,0)站点上车，要赶去（x,y）这个点，公交车只能沿着x轴开，问最快到x,y要从哪一下站下车…水题

#include<cstdio>#include<cmath>#include<cstring>#include<iostream>#include<algorithm>using namespace std;#define INF 0x3f3f3f3ftypedef long long ll;const double eps=1e-8;int sgn(double a){return a<-eps?-1:a<eps?0:1;}double dis(double x1,double y1,double x2){    return sqrt((x1-x2)*(x1-x2)+y1*y1);}int st[105];int main(){    int n,vb,vs,tx,ty;    scanf("%d%d%d",&n,&vb,&vs);    for(int i=0;i<n;i++) scanf("%d",&st[i]);    scanf("%d%d",&tx,&ty);    double ans=INF;int ansi=0;    for(int i=1;i<n;i++)    {        double t=dis(1.0*tx,1.0*ty,1.0*st[i])/vs+1.0*st[i]/vb;        if(sgn(t-ans)<=0)        {            ans=t;            ansi=i;        }    }    printf("%d\n",ansi+1);}