-
Notifications
You must be signed in to change notification settings - Fork 0
/
SegmentedSieve.java
92 lines (68 loc) · 2.28 KB
/
SegmentedSieve.java
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
//Initial Template for Java
import java.io.*;
import java.util.*;
class SegmentedSieve{
public static void main(String args[])throws IOException
{
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
int t = Integer.parseInt(in.readLine());
while(t-- > 0){
String a[] = in.readLine().trim().split("\\s+");
long L = Long.parseLong(a[0]);
long R = Long.parseLong(a[1]);
Solution ob = new Solution();
System.out.println(ob.primeProduct(L, R));
}
}
}// } Driver Code Ends
//User function Template for Java
class Solution{
static long mod = 1000000007;
static long primeProduct(long l, long r){
//make root of upper range
long rootr = (long)Math.sqrt(r);
int n = (int)(r-l+1);
boolean[] arr = new boolean[n];
Arrays.fill(arr, true);
//get prime till root r
ArrayList<Long> primes = sieve(rootr);
//marking using prime
for(long prime: primes){
long multiple = (long)Math.ceil((l*1.0)/prime);
if(multiple==1)
multiple++;
long idx = multiple*prime - l;
for(long j=idx; j<arr.length; j +=prime){
if(arr[(int)j]){
arr[(int)j] = false;
}
}
}
long res = 1;
for(long i=0; i<arr.length; i++){
if(arr[(int)i]==true && i+l>1){
res = (res * (i+l))%mod;
}
}
return res % mod;
}
public static ArrayList<Long> sieve(long r){
int n = (int)r+1;
boolean[] arr = new boolean[n];
ArrayList<Long> res = new ArrayList<>();
Arrays.fill(arr, true);
for(int i=2; i*i<arr.length; i++){
if(arr[i]){
for(int j = i+i; j<arr.length; j+=i){
arr[j] = false;
}
}
}
for(int i=2; i<arr.length; i++){
if(arr[i]==true){
res.add((long)i);
}
}
return res;
}
}