https://www.acmicpc.net/problem/5613
= 문자가 들어오기전까지 (+,-,*,/) 와 숫자를 계산된 값에 사칙연산 하는 것으로 접근했다.
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 answer = Integer.parseInt(br.readLine());
while (true) {
String operator = br.readLine();
if (operator.equals("="))
break;
int secondNum = Integer.parseInt(br.readLine());
if (operator.equals("+"))
{
answer += secondNum;
}else if (operator.equals("-"))
{
answer -= secondNum;
}else if (operator.equals("*"))
{
answer *= secondNum;
}else {
// 나눗셈
answer /= secondNum;
}
}
System.out.println(answer);
}
}