51 lines
862 B
C++
51 lines
862 B
C++
#include<cstdio>
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#include<cstring>
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#include<algorithm>
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using namespace std;
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int a[15];
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int n,m;
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int gcd(int a,int b)
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{
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if(!b)
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return a;
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else
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return gcd(b,a%b);
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}
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int ans;
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int kk;
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void dfs(int val,int s,int k,int cnt)
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{
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if(cnt>k)
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return;
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if(k==cnt)
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{
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if(cnt%2)
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ans+=m/val;
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else
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ans-=m/val;
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return;
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}
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for(int i=s+1;i<=kk;i++)
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dfs(val/gcd(a[i],val)*a[i],i,k,cnt+1);
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}
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int main()
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{
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int i;
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while(scanf("%d%d",&m,&n)!=EOF)
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{
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m--;
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kk=0;
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for(i=1;i<=n;i++)
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{
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scanf("%d",&a[i]);
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if(a[i])
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a[++kk]=a[i];
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}
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ans=0;
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for(i=1;i<=kk;i++)
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dfs(1,0,i,0);
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printf("%d\n",ans);
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}
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return 0;
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}
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