41 lines
602 B
C++
41 lines
602 B
C++
#include<iostream>
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using namespace std;
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long double f_j(int sr)
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{
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if(sr<0) return 0;
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if(sr==0) return 1;
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return sr*f_j(sr-1);
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}
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long double C(int x,int y)
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{
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return f_j(x)/f_j(x-y)/f_j(y);
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}
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long double big_(long double a,long double b)
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{
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return (a>b)?a:b;
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}
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long double small_(long double a,long double b)
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{
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return (a<b)?a:b;
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}
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int main()
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{
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int n,add;
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while(true)
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{
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cin>>n;
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add=0;
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for(int one=0;one<=n;one++)
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{
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for(int two=0;two<=n/2;two++)
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{
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if(one+two*2==n)
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{
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add+=C(big_(one,two)+small_(one,two),small_(one,two));
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}
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}
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}
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cout<<add<<endl;
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}
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}
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