34 lines
582 B
C++
34 lines
582 B
C++
#include <stdio.h>
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using namespace std;
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#define N 100000001
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int euler(int n)
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{
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int ans=1;
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int i;
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for(i=2;i*i<=n;i++)
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{
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if(n%i==0)
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{
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n/=i;
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ans*=i-1;
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while(n%i==0)
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{
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n/=i;
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ans*=i;
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}
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}
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}
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if(n>1)
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ans*=n-1;
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return ans;
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}
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int main()
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{
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int n;
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while(scanf("%d",&n),n)
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{
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printf("%d\n",n-1-euler(n));
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}
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return 0;
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}
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