PAT1013 number prime

1013 number prime numbers (20 minutes)

 

So that  P i represents  the i-th prime number. The current to the two positive integers  M ≤ N ≤ . 1 0 . 4 , please output  P M to  P N all prime numbers.

Input formats:

In the given input row  M and  N, separated by a space therebetween.

Output formats:

Output from the  P M to  P N all prime numbers, each representing a digit line 10, separated by spaces therebetween, the end of the line may not have extra space.

Sample input:

5 27

Sample output:

11 13 17 19 23 29 31 37 41 43
47 53 59 61 67 71 73 79 83 89
97 101 103


Ideas: the use of "Eppendorf" sieve 
Memory: 1,000,000 (10 ^ 6) of the prime number 78498, 10000000 (10 ^ 7) of the prime number 664579

 1 #include <iostream>
 2 #include <cstring>
 3 #include <algorithm>
 4 
 5 using namespace std ;
 6 
 7 const int N = 10000010 ;
 8 
 9 bool st[N] ;
10 int primes[N] ;
11 int n, m ; 
12  
13  
14 int main(){
15     cin >> n >> m ;
16     
17     int idx = 0 ;
18     
19     for(int i=2;i<10000010;i++){
20         if(!st[i]){
21             primes[idx++] = i ;
22             if(idx == m){
23                 break ;
24             }
25             for(int j=i;j<=10000010;j += i){
26                 st[j] = true ;
27             }
28         }
29     }
30     idx = 0 ;
31     for(int i=n-1;i<m;i++){
32         idx ++ ;
33         if(idx==10 || i==m-1){
34             printf("%d\n",primes[i]) ;
35             idx = 0 ;
36         }else{
37             printf("%d ",primes[i]) ;
38         }
39     }
40     
41     return 0 ;    
42 }