import java.util.Scanner;
public class Main {
public static void main(String[] args) {
System.out.println("Input the number(n):");
Scanner s = new Scanner(System.in);
int c = s.nextInt();
int ans = check(c);
System.out.println("Number of prime numbers which are less than or equal to n.:");
System.out.println(ans);
}
static int check(int c) {
boolean[] prime = new boolean[c+1];
int count = 0;
for(int i = 2; i <= Math.sqrt(c); i++) {
for(int j = i + i; j <= c; j += i) {
prime[j] = true;
}
}
for(int i = 2; i <= c; i++) {
if(!prime[i]) {
count++;
}
}
return count;
}
}
Sample Output:
Input the number(n):
1235
Number of prime numbers which are less than or equal to n.:
202
Sample Output:
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