The program must accept T pairs of integers as the input. For each pair P (P contains two integers X and Y) among the T pairs, the program must print all the prime numbers from X to Y (inclusive) in ascending order as the output. If there is no prime number from X to Y then the program must print -1 for that pair as the output.
Boundary Condition(s):
1 <= T <= 10^4
1 <= X < Y <= 10^9
Input Format:
The first line contains the value of T.
The next T lines containing a pair of integers separated by a space.
Output Format:
The first T lines containing the prime numbers of each pair separated by a space as per the given conditions.
Example Input/Output 1:
Input:
3
10 20
1 15
32 36
Output:
11 13 17 19
2 3 5 7 11 13
-1
Explanation:
The first pair is (10, 20). So the prime numbers from 10 to 20 are printed.
The second pair is (1, 15). So the prime numbers from 1 to 15 are printed.
The third pair is (32, 36). Here there is no prime number from 32 to 36. So -1 is printed.
Example Input/Output 2:
Input:
6
51 68
15 75
21 97
2 55
8 81
80 100
Output:
53 59 61 67
17 19 23 29 31 37 41 43 47 53 59 61 67 71 73
23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97
2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53
11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79
83 89 97
#include<stdio.h>
#include<stdlib.h>
int isprime(int n){
if (n<=1)
return 0;
if (n<=3)
return 1;
if (n%2==0 || n%3==0)
return 0;
int i=5;
while(i*i<=n){
if (n%i==0 || n%(i+2)==0)
return 0;
i+=6;
}
return 1;
}
int main()
{
int t;
scanf("%d",&t);
while(t-- > 0){
long long int x,y;
scanf("%lld %lld",&x,&y);
int flag=0;
if (x<=2){
printf("2 ");
flag=1;
x=3;
}
else
x+=(x%2==0);
while(x<=y){
if(isprime(x)){
printf("%d ",x);
flag=1;
}
x+=2;
}
if (flag==0)
printf("-1");
printf("n");
}
}Source: https://github.com/kishorercse
