提出 #485279

---

ソースコード 拡げる

#include<bits/stdc++.h>
using namespace std;
const double pi = 2 * acos(0.0);
const double eps = 1e-8;
int main(){
	double x,y,O,w;
	scanf("%lf%lf%lf%lf",&x,&y,&O,&w);
	O = O / 180.0 * pi;
	w = w / 180.0 * pi;
	double theta = atan2(y,x);
	//printf("%.f\n",theta*180/pi);
	if(theta<eps)theta+=2*pi;
	double d = sqrt(x*x+y*y);
	double sx=cos(O),sy=sin(O);

	double l = 0.0,r = w*d;
	while(r-l>eps){
		double mid = (l+r)/2;
		double ra = mid / w;
		double t = sqrt(d*d-ra*ra);
		double myt = t / mid;
		double a = acos((d*d+ra*ra-t*t)/2.0/d/ra);
		double a1=theta+a,a2=theta-a;
		if(a1>2*pi)a1-=2*pi;
		if(a2<0)a2+=2*pi;
		
		double mx=cos(a1),my=sin(a1);
		if((sx*y-sy*x)*(sx*my-sy*mx)<eps)a1=-1.0;
		else {
			a1=fabs(a1-O);
			a1=min(a1,2*pi-a1);
		}

		mx=cos(a2),my=sin(a2);
		if((sx*y-sy*x)*(sx*my-sy*mx)<eps)a2=-1.0;
		else {
			a2=fabs(a2-O);
			a2=min(a2,2*pi-a2);
		}
		if(a1<0&&a2<0){
			r=mid;
			continue;
		}
		double st = max(a1,a2);
		st = st / w;
		if(st+eps<myt)l=mid;
		else r=mid;
	}
	printf("%.8f\n",l);
	return 0;
}

提出情報

コンパイルエラー

./Main.cpp: In function ‘int main()’:
./Main.cpp:7:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lf%lf%lf%lf",&x,&y,&O,&w);
                                   ^

ジャッジ結果