41 lines
760 B
C++
41 lines
760 B
C++
#include <iostream>
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#include <cstring>
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#include <cstdio>
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#include <cmath>
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using namespace std;
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const double pi=acos(-1.0);
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const double g=9.8;
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double v,h;
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double ans(double a)
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{
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double a1=v*v*sin(a)*sin(a);
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double a2=2*g*h;
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a1=a1+a2;
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a1=sqrt(a1);
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a1=a1/g;
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a1=a1+v*sin(a)/g;
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a1=a1*v*cos(a);
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return a1;
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}
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int main()
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{
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int T;
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scanf("%d",&T);
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while (T--)
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{
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scanf("%lf%lf",&h,&v);
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double l=0;
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double r=pi/2;
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while (r-l>=0.0000001)
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{
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double m=(l+r)/2;
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double mm=(m+r)/2;
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if (ans(m)<ans(mm))
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l=m;
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else
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r=mm;
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}
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printf("%.2f\n",ans(l));
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}
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}
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