백준 - 소수찾기(1978)

⭐문제 : https://www.acmicpc.net/problem/1978

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int count = Integer.parseInt(br.readLine());

        String input = br.readLine();
        String[] wordArr = input.split(" ");

        for(String word : wordArr){
            int num = Integer.parseInt(word);
            if(num==1||(num%2==0&&num!=2)) {
                count--;
                continue;
            }
            for(int i=2; i*i<=num; i++){
                if(num%i==0) {
                    count--;
                    break; //여러개의 인수를 가지는 num을 중복 카운팅 안시킴
                }
            }
        }
        System.out.println(count);
    }
}