[Week01] BOJ_10828: 스택

Author: sukangpunch

weekly/week01/BOJ_10828_스택/sukangpunch.java

@@ -0,0 +1,71 @@
+package stduy.week01;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+// 스택
+public class BOJ_10828 {
+    static class MyStack{
+        int [] st;
+        int top;
+
+        public MyStack(int size){
+            this.st = new int[size];
+            this.top = -1;
+        }
+
+        public void push(int x){
+            st[++top] = x;
+        }
+
+        public int pop(){
+            if(top == -1){
+                return -1;
+            }
+
+            return st[top--];
+        }
+
+        public int size(){
+            return top + 1;
+        }
+
+        public int empty(){
+            if(top == -1){
+                return 1;
+            }
+
+            return 0;
+        }
+
+        public int top(){
+            if(top == -1){
+                return -1;
+            }
+
+            return st[top];
+        }
+    }
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringBuilder sb = new StringBuilder();
+
+        int N = Integer.parseInt(br.readLine());
+
+        MyStack stack = new MyStack(N);
+        for (int i = 0; i < N; i++) {
+            String []s = br.readLine().split(" ");
+
+            switch(s[0]){
+                case "push": stack.push(Integer.parseInt(s[1])); break;
+                case "pop": sb.append(stack.pop()).append("\n"); break;
+                case "size": sb.append(stack.size()).append("\n"); break;
+                case "empty": sb.append(stack.empty()).append("\n"); break;
+                case "top": sb.append(stack.top()).append("\n"); break;
+            }
+        }
+        System.out.println(sb);
+    }
+}