feat: initial repo scaffolding

Port in some older solutions I've written just to
get the structure established and in place.

src/leetcode/backspace-string-compare/main.spec.ts

@@ -0,0 +1,19 @@
+/**
+ * @copyright NHCarrigan
+ * @license Naomi's Public License
+ * @author Naomi Carrigan
+ */
+
+import { describe, it, expect } from "vitest";
+import { backspaceCompare } from "./main.js";
+
+describe("backspaceCompare", () => {
+  it("should return true if the strings are equal", () => {
+    expect(backspaceCompare("ab#c", "ad#c")).toBe(true);
+    expect(backspaceCompare("ab##", "c#d#")).toBe(true);
+  });
+
+  it("should return false if the strings are not equal", () => {
+    expect(backspaceCompare("ab#c", "b")).toBe(false);
+  });
+});

src/leetcode/backspace-string-compare/main.ts

@@ -0,0 +1,53 @@
+/**
+ * @copyright NHCarrigan
+ * @license Naomi's Public License
+ * @author Naomi Carrigan
+ */
+
+/**
+ * Compares two strings to see if they are equal when both are typed into empty text editors.
+ * '#' means a backspace character.
+ * @param s - The first string to compare.
+ * @param t - The second string to compare.
+ * @returns True if the strings are equal, false otherwise.
+ * @see https://leetcode.com/problems/backspace-string-compare/description/
+ */
+const backspaceCompare = (s: string, t: string): boolean => {
+  let sIndex = s.length - 1;
+  let tIndex = t.length - 1;
+  let sSkips = 0;
+  let tSkips = 0;
+
+  while (sIndex >= 0 || tIndex >= 0) {
+    while (sIndex >= 0) {
+      if (s[sIndex] === "#") {
+        sSkips = sSkips + 1;
+        sIndex = sIndex - 1;
+      } else if (sSkips > 0) {
+        sSkips = sSkips - 1;
+        sIndex = sIndex - 1;
+      } else {
+        break;
+      }
+    }
+    while (tIndex >= 0) {
+      if (t[tIndex] === "#") {
+        tSkips = tSkips + 1;
+        tIndex = tIndex - 1;
+      } else if (tSkips > 0) {
+        tSkips = tSkips - 1;
+        tIndex = tIndex - 1;
+      } else {
+        break;
+      }
+    }
+    if (s[sIndex] !== t[tIndex]) {
+      return false;
+    }
+    sIndex = sIndex - 1;
+    tIndex = tIndex - 1;
+  }
+  return true;
+};
+
+export { backspaceCompare };