mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
46 lines
816 B
C++
46 lines
816 B
C++
#include<iostream>
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#include<string.h>
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#include<cstdio>
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using namespace std;
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#define LL long long
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#define M 3100300
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int tag[M],p[M];
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void Prime()
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{
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memset(tag,0,sizeof(tag));
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memset(p,0,sizeof(p));
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int cnt=0,i,j;
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for( i=2;i<M;i++)
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{
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if(!tag[i])
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p[cnt++]=i;
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for( j=0;j<cnt&&p[j]*i<M;j++)
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{
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tag[i*p[j]]=1;
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if(i%p[j]==0)
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break;
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}
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}
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memset(p,0,sizeof(p));
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for( i=1;i<M/3;i++)
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{
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LL t=3*i+7;
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if(tag[t]==0)
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p[i]=p[i-1]+1;
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else
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p[i]=p[i-1];
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}
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}
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int main()
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{
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int n,t;
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Prime();
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scanf("%d",&t);
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while(t--)
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{
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scanf("%d",&n);
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printf("%d\n",p[n]);
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}
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return 0;
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}
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