15 lines
247 B
C++
15 lines
247 B
C++
#include<cstdio>
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#include<cmath>
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memset(vis,0,sizeof(vis));
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int get_prime_nums(int n){ //返回1 ~ 10^n素数个数的位数
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double m=double(n-log10(n)-log10(log(10)));
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return int(m)+1;
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}
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int main()
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{
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int n=12;
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printf("%d",get_prime_nums(n));
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}
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