Closest Prime (Contest)
Problem Statement
Given an integer N, find the closest prime number to N. If there are multiple print the smaller one.
import java.io.*; // for handling input/output
import java.util.*; // contains Collections framework
// don't change the name of this class
// you can add inner classes if needed
class Main {
public static void main (String[] args) {
Scanner sc= new Scanner(System.in);
int n=sc.nextInt();
int ad=1;
for(int i=n;i>=Math.sqrt(n);i--){
if(prime(i)){
System.out.println(i);
break;
}else if(prime(n-ad)){
System.out.println(n-ad);
break;
}else if(prime(n+ad)){
System.out.println(n+ad);
break;
}
ad++;
}
}
static boolean prime(int n){
if(n<=1)
return false;
for(int i=2;i<=Math.sqrt(n);i++){
if(n%i==0)
return false;
}
return true;
}
}
