/
CPRIME2.cpp
115 lines (87 loc) · 1.23 KB
/
CPRIME2.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
#include<bitset>
#include<iostream>
#include<vector>
#include<cmath>
#include<cstdio>
#include<cassert>
using namespace std;
#define MAX 100000005
#define SIZE 20000005
bitset<MAX> arr;
long long int val[SIZE];
int cnt;
void mark_all(int i)
{
for(int j=i*i;j<MAX;j=j+i+i)
arr.set(j,true);
}
int main()
{
int NUM=sqrt(MAX),n;
arr.reset();
arr[0]=1;
arr[1]=1;
for(int i=4;i<MAX;i+=2)
arr.set(i,true);
for(int i=9;i<MAX;i+=6)
arr.set(i,true);
for(int i=0;i<SIZE;i++)
val[i]=0;
val[0]=2;
bool flag=true;
int i;
for(i=5;i<NUM;)
{
int k=i/5;
if(!val[k])
val[k]=val[k-1];
if(!arr.test(i))
{
val[k]++;
mark_all(i);
}
if(flag)
{
flag=0;
i+=2;
}
else
{
flag=1;
i+=4;
}
}
for(;i<MAX;)
{
int k=i/5;
if(!val[k])
val[k]=val[k-1];
if(!arr.test(i))
val[k]++;
if(flag)
{
flag=0;
i+=2;
}
else
{
flag=1;
i+=4;
}
}
while(1)
{
scanf("%d",&n);
if(n==0)
return 0;
float calc=0;
int num=n/5-1;
if(num>=0)
calc=val[num];
for(int i=5*(num+1);i<=n;i++)
if(!arr.test(i))
calc++;
cout<<calc<<"\n";
printf("%0.1f\n",abs((float)calc - (float)(n/log(n)))/(float)calc *100);
}
}