[20250710] BOJ / G2 / 후위 표기식 / 권혁준

Author: oncsr

khj20006/202507/10 BOJ G2 후위 표기식.md

@@ -0,0 +1,131 @@
+```java
+import java.util.*;
+import java.io.*;
+
+class IOController {
+    BufferedReader br;
+    BufferedWriter bw;
+    StringTokenizer st;
+
+    public IOController() {
+        br = new BufferedReader(new InputStreamReader(System.in));
+        bw = new BufferedWriter(new OutputStreamWriter(System.out));
+        st = new StringTokenizer("");
+    }
+
+    String nextLine() throws Exception {
+        String line = br.readLine();
+        st = new StringTokenizer(line);
+        return line;
+    }
+
+    String nextToken() throws Exception {
+        while (!st.hasMoreTokens()) nextLine();
+        return st.nextToken();
+    }
+
+    int nextInt() throws Exception {
+        return Integer.parseInt(nextToken());
+    }
+
+    long nextLong() throws Exception {
+        return Long.parseLong(nextToken());
+    }
+
+    double nextDouble() throws Exception {
+        return Double.parseDouble(nextToken());
+    }
+
+    void close() throws Exception {
+        bw.flush();
+        bw.close();
+    }
+
+    void write(String content) throws Exception {
+        bw.write(content);
+    }
+
+}
+
+public class Main {
+
+    static IOController io;
+
+    //
+
+    static char[] a;
+
+    public static void main(String[] args) throws Exception {
+
+        io = new IOController();
+
+        init();
+        solve();
+
+        io.close();
+    }
+
+    public static void init() throws Exception {
+
+        a = io.nextLine().toCharArray();
+
+    }
+
+    static void solve() throws Exception {
+
+        Deque<String> d = new ArrayDeque<>();
+        for(int i=0;i<a.length;i++) d.offerLast(Character.toString(a[i]));
+        io.write(get(d));
+
+    }
+
+    static String get(Deque<String> d) {
+        Deque<String> d1 = new ArrayDeque<>();
+        while(!d.isEmpty()) {
+            String a = d.pollFirst();
+            if(a.equals(")")) {
+                String last;
+                Deque<String> temp = new ArrayDeque<>();
+                while(!(last = d1.pollLast()).equals("(")) temp.offerFirst(last);
+                d1.addLast(get(temp));
+            }
+            else d1.addLast(a);
+        }
+
+        Deque<String> d2 = new ArrayDeque<>();
+        while(!d1.isEmpty()) {
+            String a = d1.pollFirst();
+            if(d2.isEmpty()) {
+                d2.addLast(a);
+                continue;
+            }
+            String last = d2.peekLast();
+            if(last.equals("*") || last.equals("/")) {
+                d2.pollLast();
+                String llast = d2.pollLast();
+                d2.addLast(llast + a + last);
+            }
+            else d2.addLast(a);
+        }
+
+        Deque<String> d3 = new ArrayDeque<>();
+        while(!d2.isEmpty()) {
+            String a = d2.pollFirst();
+            if(d3.isEmpty()) {
+                d3.addLast(a);
+                continue;
+            }
+            String last = d3.peekLast();
+            if(last.equals("+") || last.equals("-")) {
+                d3.pollLast();
+                String llast = d3.pollLast();
+                d3.addLast(llast + a + last);
+            }
+            else d3.addLast(a);
+        }
+
+        return d3.poll();
+    }
+
+}
+```