20 lines
380 B
C++
20 lines
380 B
C++
#include<iostream>
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#include<cstdio>
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#include<cstring>
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#include<cmath>
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#include<algorithm>
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using namespace std;
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int main()
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{
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int T,a,b;
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scanf("%d",&T);
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for (int i=1;i<=T;i++)
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{
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scanf("%d%d",&a,&b);
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double a1=1-pow(1-1.0/a,b);
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double x=a;
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double ans=x*(x+1)/2*a1;
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printf("Case #%d: %.3lf\n",i,ans);
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}
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}
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