adds ts for tree searches

ts/bfs.test.ts

@@ -0,0 +1,38 @@
+import { tree } from "./tree"
+
+type BinaryNode<T> = {
+    value: T;
+    left: BinaryNode<T> | null;
+    right: BinaryNode<T> | null;
+};
+
+
+function bfs(head: BinaryNode<number> | null, needle: number): boolean {
+    const q: (BinaryNode<number> | null)[] = [head];
+
+    while (q.length) {
+        const current = q.shift() as BinaryNode<number>;
+
+        if (current.value === needle) {
+            return true;
+        }
+
+        if (current.left) {
+            q.push(current.left);
+        }
+
+        if (current.right) {
+            q.push(current.right);
+        }
+    }
+
+    return false;
+}
+
+
+test("bfs search works a number of values", function () {
+    expect(bfs(tree, 20)).toEqual(true);
+    expect(bfs(tree, -20)).toEqual(false);
+    expect(bfs(tree, 10)).toEqual(true);
+    expect(bfs(tree, 7)).toEqual(true);
+})

ts/tree.ts

@@ -0,0 +1,47 @@
+type BinaryNode<T> = {
+    value: T;
+    left: BinaryNode<T> | null;
+    right: BinaryNode<T> | null;
+};
+
+export const tree: BinaryNode<number> = {
+    value: 20,
+    right: {
+        value: 50,
+        right: {
+            value: 100,
+            right: null,
+            left: null,
+        },
+        left: {
+            value: 30,
+            right: {
+                value: 45,
+                right: null,
+                left: null,
+            },
+            left: {
+                value: 29,
+                right: null,
+                left: null,
+            }
+        },
+    },
+    left: {
+        value: 10,
+        right: {
+            value: 15,
+            right: null,
+            left: null,
+        },
+        left: {
+            value: 5,
+            right: {
+                value: 7,
+                right: null,
+                left: null,
+            },
+            left: null,
+        }
+    }
+};

ts/tree_traversal.test.ts

@@ -0,0 +1,44 @@
+import { tree } from "./tree"
+
+type BinaryNode<T> = {
+    value: T;
+    left: BinaryNode<T> | null;
+    right: BinaryNode<T> | null;
+};
+
+// pre order 
+function walk(current: BinaryNode<number> | null, path: number[]): number[] {
+    if (!current) {
+        return path;
+    }
+
+    path.push(current.value);
+    walk(current.left, path);
+    walk(current.right, path);
+
+    return path;
+
+}
+
+function pre_order_search(head: BinaryNode<number>): number[] {
+    const path: number[] = [];
+    walk(head, path);
+
+    return path;
+
+}
+
+test("Pre order", function () {
+    expect(pre_order_search(tree)).toEqual([
+        20,
+        10,
+        5,
+        7,
+        15,
+        50,
+        30,
+        29,
+        45,
+        100,
+    ]);
+});