[20250311] BOJ / G2 / 후위 표기식 / 설진영

Author: Seol-JY

Seol-JY/202503/11 BOJ G2 후위 표기식.md

@@ -0,0 +1,54 @@
+```java
+import java.io.*;
+import java.util.ArrayDeque;
+
+public class Main {
+    static ArrayDeque<Character> stack = new ArrayDeque<>();
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringBuilder sb = new StringBuilder();
+        String userInput = br.readLine();
+
+        for (int i = 0; i < userInput.length(); i++) {
+            char target = userInput.charAt(i);
+
+            switch(target) {
+                case '+':
+                case '-':
+                case '*':
+                case '/':
+                    while (!stack.isEmpty() && priority(stack.peek()) >= priority(target)) {
+                        sb.append(stack.pop());
+                    }
+                    stack.push(target);
+                    break;
+                case '(':
+                    stack.push(target);
+                    break;
+                case ')':
+                    while (!stack.isEmpty() && stack.peek() != '(') {
+                        sb.append(stack.pop());
+                    }
+                    stack.pop();
+                    break;
+                default:
+                    sb.append(target);
+            }
+        }
+        
+        while (!stack.isEmpty()) {
+            sb.append(stack.pop());
+        }
+        
+        System.out.println(sb.toString());
+    }
+
+    public static int priority(char op) {
+        if (op == '(' || op ==')') return 0;
+        if (op == '+' || op == '-') return 1;
+        if (op == '*' || op == '/') return 2;
+        return -1;
+    }
+}
+```