37 lines
702 B
C++
37 lines
702 B
C++
#include<stdio.h>
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#include<math.h>
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double r, R, H, V;
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double volume( double h )
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{
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double u = r + ( R- r ) * h / H;
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return ( 3.1415926535897932384626433832795* h * (u* u + r * u + r * r) / 3.0 );
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}
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double erfen(double bottom,double top)
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{
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double mid;
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while(top-bottom>1e-10)
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{
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mid=(top+bottom)/2;
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if(volume(mid)>V)
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{
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top=mid-1e-11;
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}
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else
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{
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bottom=mid+1e-11;
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}
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}
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return (bottom+top)/2;
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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 %lf %lf", &r, &R, &H, &V);
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printf("%.6lf\n",erfen(0,H));
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}
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return 0;
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}
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