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https://github.com/Kiritow/OJ-Problems-Source.git
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40 lines
658 B
C++
40 lines
658 B
C++
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#include <iostream>
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using namespace std;
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int gcd(int a,int b)
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{
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return b==0?a:gcd(b,a%b);
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}
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__int64 pow(int a,int b)
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{
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__int64 s=1;
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for(int i=0;i<b;i++)
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s*=a;
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return s;
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}
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int main()
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{
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int n,i;
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__int64 ans;
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while(cin>>n)
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{
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ans=0;
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if(n>=40)continue;
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if(n<0)break;
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if(n==0){ printf("0\n");continue; }
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for(i=1;i<=n;i++)
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ans+=pow(3,gcd(n,i));
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if(n%2)
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{
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ans+=( pow(3,(n+1)/2) *n);
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}
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else
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{
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ans+=( pow(3,n/2+1) * n/2);
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ans+=( pow(3,n/2) *n/2 );
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}
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ans/=(2*n);
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printf("%I64d\n",ans);
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}
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return 0;
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}
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