[백준_JAVA] 25206 너의 평점은

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String subject = ""; // 과목
		double credit = 0.0; // 학점시수
		String grade = ""; // 학점(문자)
		double sum = 0.0; // 학점시수*학점
		int count = 0; // 과목 시수
		
		
		for(int i = 0; i < 20; i++){
			subject = scan.next();
			credit = scan.nextDouble();
			grade = scan.next();
			
			if(grade.equals("A+")) {sum += credit*4.5; count += credit;}
			if(grade.equals("A0")) {sum += credit*4.0; count += credit;}
			if(grade.equals("B+")) {sum += credit*3.5; count += credit;}
			if(grade.equals("B0")) {sum += credit*3.0; count += credit;}
			if(grade.equals("C+")) {sum += credit*2.5; count += credit;}
			if(grade.equals("C0")) {sum += credit*2.0; count += credit;}
			if(grade.equals("D+")) {sum += credit*1.5; count += credit;}
			if(grade.equals("D0")) {sum += credit*1.0; count += credit;}
			if(grade.equals("F")) {sum += credit*0.0; count += credit;}
		}
		System.out.printf("%.6f", (sum/count));
	}
}