[Example] Stack

app/examples/binary-search.recho.js

@@ -2,8 +2,8 @@
  * @title Binary Search
  * @author Bairui Su
  * @github pearmini
- * @created 2025-12-09
- * @label Algorithm, Beginner
+ * @created 2025-12-08
+ * @label Algorithm
  * @pull_request 200
  */
 

app/examples/stack.recho.js

@@ -0,0 +1,97 @@
+/**
+ * @title Stack
+ * @author Bairui Su
+ * @github pearmini
+ * @created 2025-12-09
+ * @label Algorithm
+ * @thumbnail_start 20
+ * @pull_request 201
+ */
+
+/**
+ * ============================================================================
+ * =                                Stack                                     =
+ * ============================================================================
+ *
+ * This example demonstrates a classic Stack data structure with push and pop
+ * operations. A stack follows the LIFO (Last In, First Out) principle. The
+ * following is a simple demonstration of how it looks like.
+ */
+
+const [stack, setStack] = recho.state(new Stack());
+
+//➜ "gol\\hRXCro^^suA"
+echo(stack.items.join(""));
+
+// Push button - adds a random alphabet character to the stack
+recho.button("Push", push);
+
+// Pop button - removes the top element from the stack
+recho.button("Pop", pop);
+
+/**
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *                               Implementation
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * The stack is implemented as a class with a few methods:
+ *
+ * - `push(element)`: adds an element to the stack
+ * - `pop()`: removes the top element from the stack
+ * - `clone()`: creates a deep copy of the stack
+ *
+ */
+
+class Stack {
+  constructor() {
+    this.items = [];
+  }
+
+  push(element) {
+    this.items.push(element);
+  }
+
+  pop() {
+    if (this.items.length === 0) return undefined;
+    return this.items.pop();
+  }
+
+  clone() {
+    const cloned = new Stack();
+    cloned.items = [...this.items];
+    return cloned;
+  }
+}
+
+/**
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *                               Helper Functions
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * The following are helper functions to push and pop elements from the stack,
+ * and a function to generate a random alphabet character (A-z).
+ */
+
+function push() {
+  setStack((s) => {
+    const cloned = s.clone();
+    cloned.push(randomAlphabet());
+    return cloned;
+  });
+}
+
+function pop() {
+  setStack((s) => {
+    const cloned = s.clone();
+    cloned.pop();
+    return cloned;
+  });
+}
+
+// Function to generate a random alphabet character (A-z)
+function randomAlphabet() {
+  // Generate random character from A (65) to z (122)
+  // This includes A-Z (65-90), some special chars (91-96), and a-z (97-122)
+  const code = Math.floor(Math.random() * (122 - 65 + 1)) + 65;
+  return String.fromCharCode(code);
+}