[4949] 균형잡힌 세상 - Java

 

1. 문제

https://www.acmicpc.net/problem/4949

4949번: 균형잡힌 세상

 

2. 풀이

 

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

public class Main {

	public static void main(String[] args) throws IOException{

		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		Stack <Character> stack = new Stack();

		String str; // String case to read
		String answer;  // default = yes

		while(true) {

			// 1. Read the String
			str = br.readLine();

			// 2. See if the String is balanced
			char word;
			
			answer = "yes";
			for(int i = 0; i < newStr.length(); i++){
				
				word = newStr.charAt(i);
				
				// if stack is empty
				if(stack.isEmpty()) {
					// a. if closing parenthesis come first
					if((word == ')' || word == ']')) {
						answer = "no";
						break;
					}else if(word == '(' || word == '[') {
						stack.push(word);
					}

				// stack not empty
				}
				else {
					
					if(stack.peek() == '(') {

						if(word == '(' || word == '[') {
							stack.push(word);
						}else if(word == ')') {
							stack.pop();
						}else if(word == ']'){
							answer = "no";
							break;
						}

					}else if(stack.peek() == '[') {

						if(word == '(' || word == '[') {
							stack.push(word);
						}else if(word == ']') {
							stack.pop();
						}else if(word == ')'){
							answer = "no";
							break;
						}
					}
				}
			}
            // 4. Final check
			if(!stack.isEmpty()) {
				answer = "no";
			}
			
			// 5. Clear stack
			stack.clear();
			
            // 7. End while loop
			if(str.equals(".")) {
				break;
			}
            
            // 6. Print result
			System.out.println(answer);
		}
	}
}

 

3. 배운점

- 문제를 잘 읽어야 한다. 마지막 '.'은 종료 조건이며 결과 값은 출력하지 않아도 된다.

 

4. 개선할 점