[Java] 백준 - 15851번 천재 수학자 성필 (Silver III)

📝 문제

백준 - 15851번 천재 수학자 성필 (Silver III)

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📝 풀이

📌 작성 코드

import java.io.*;
import java.util.*;
public class Main {
	public static void main(String[] args) throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		
		String[] arr = br.readLine().split("");
		
		Stack<Integer> numbers = new Stack<>();
		Queue<Character> signs = new LinkedList<>();
		
		String sign = "+-*/";
		for (int i = 0; i < arr.length; i++) {
			if (i == 0) {
				numbers.push(Integer.parseInt(arr[i]));
			} else {
				if (sign.indexOf(arr[i]) == -1) {
					if (sign.indexOf(arr[i-1]) != -1) {
						func(numbers, signs);
						numbers.push(Integer.parseInt(arr[i]));
					} else {
						numbers.push(Integer.parseInt(arr[i]));
					}
				} else {
					signs.add(arr[i].charAt(0));
				}
			}
		}

		func(numbers, signs);
		
		System.out.println(numbers.pop());
	}
	
	public static void func(Stack<Integer> numbers, Queue<Character> signs) {
		while(!signs.isEmpty()) {
			char sign = signs.poll();
			
			int a = numbers.pop();
			int b = numbers.pop();
			
			if (sign == '+') {
				numbers.push(a + b);
			} else if (sign == '-') {
				numbers.push(b - a);
			} else if (sign == '*') {
				numbers.push(a * b);
			} else {
				numbers.push(b / a);
			}
		}
	}
}

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📌 결과