PRIME1 - Prime Generator


Peter wants to generate some prime numbers for his cryptosystem. Help him! Your task is to generate all prime numbers between two given numbers!

Input

The input begins with the number t of test cases in a single line (t<=10). In each of the next t lines there are two numbers m and n (1 <= m <= n <= 1000000000, n-m<=100000) separated by a space.

Output

For every test case print all prime numbers p such that m <= p <= n, one number per line, test cases separated by an empty line.

Example

Input:
2
1 10
3 5

Output:
2
3
5
7

3
5
Warning: large Input/Output data, be careful with certain languages (though most should be OK if the algorithm is well designed)

Information

After cluster change, please consider PRINT as a more challenging problem.

hide comments
shreyansh96: 2017-07-18 18:19:14

Why am i getting SIGSEV?

jangir_1: 2017-07-18 17:22:01

time limit is exceeds what to do , can any one help??
here is my code.....
#include <iostream>
using namespace std;



int prim(){
int a,b,f;
cin>>a>>b;
for (int i=a;i<b;i++){
f=0;
for(int j=2;j<=i/2;j++){
if (i%j==0){
f=1;
break;
}

}
if (f==0) cout<<i<<endl;
}
}
int main() {
int n;
cin>>n;
for(int k=1;k<=n;k++){
cout<<prim()<<endl;
}


// your code here

return 0;
}

skyzhi: 2017-07-16 07:19:43

AC in 0.00sec happy ?

win2009: 2017-07-16 04:01:12

Proof of my theory above/below: look at jhaanuj2108's code. It is terrible, but it uses a square root trick. He succeeded. almost NO optimizations and he still passed. Use the square root trick.

Last edit: 2017-07-16 04:15:36
win2009: 2017-07-16 03:59:17

The trick is to use the square root trick when considering factors. Sieve or no sieve does not matter. Just use the square root trick and you will be fine. Also, optimize your code. You do not have to handle the worst case scenario ( 999900000 1000000000), at least that was the case for me.

jhaanuj2108: 2017-07-15 23:00:34


import java.util.Scanner;
class PrimeGenerator {
public static boolean isPrime(int no)
{
if(no==1)
return false;
int y=(int) Math.sqrt(no);
for(int j=2;j<=y;j++)
{
if(no%j==0)
return false;
}
return true;
}
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
int t=sc.nextInt();
for(int i=0;i<t;i++)
{
int beg=sc.nextInt();
int end=sc.nextInt();
for(int j=beg;j<=end;j++)
{
if(isPrime(j))
System.out.println(j);
}
System.out.println("");
}
}


}

pyrojathon: 2017-07-14 12:09:31

Last edit: 2017-07-14 12:18:27
gabe3491: 2017-07-12 12:33:39

seriously a single line mistake ruined my day..
use segmented sieve..

Last edit: 2017-07-12 13:24:02
sravan_maddika: 2017-07-04 10:26:14

can anyone explain the code please

sidh13: 2017-07-02 17:30:07

MY code is working fine in my system in language c++ but here it shows time limit exceeded although i have tried it many times please help!!


Added by:Adam Dzedzej
Date:2004-05-01
Time limit:6s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: NODEJS PERL6