delete pics to save space

2.10566.cpp

@@ -0,0 +1,25 @@
+#include<cstdio>
+#include<cmath>
+double x,y,c,mid;
+double cal(double w)
+{ return 1-c/sqrt(x*x-w*w)-c/sqrt(y*y-w*w); }
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	while(scanf("%lf%lf%lf",&x,&y,&c)==3)
+	{
+		double r,l;
+	    r=(x<y?x:y);
+		l=0;
+		while(l+1e-9<r)
+		{
+			mid=(l+r)/2;
+			if(cal(mid)>0) l=mid;
+			else r=mid;
+		}
+		printf("%.3lf\n",l);
+	} 
+	return 0;
+}