feat: Add solution for Pascal's Triangle problem

Author: pragusga25

easy/pascals-triangle.test.ts

@@ -0,0 +1,33 @@
+// Problem: https://leetcode.com/problems/pascals-triangle/
+// Doc: https://leetcode.com/problems/pascals-triangle/solutions/5471283/generating-pascal-s-triangle-efficiently/
+const generate = (numRows: number): number[][] => {
+  const result = [[1]];
+  if (numRows === 1) return result;
+
+  for (let i = 1; i < numRows; i++) {
+    const prev = result[i - 1];
+    const row = [1];
+    for (let j = 0; j < prev.length - 1; j++) {
+      const l = prev[j];
+      const r = prev[j + 1];
+      row.push(l + r);
+    }
+    row.push(1);
+    result.push(row);
+  }
+
+  return result;
+};
+
+describe("Pascal's Triangle", () => {
+  it('should return the pascal triangle', () => {
+    expect(generate(5)).toEqual([
+      [1],
+      [1, 1],
+      [1, 2, 1],
+      [1, 3, 3, 1],
+      [1, 4, 6, 4, 1],
+    ]);
+    expect(generate(1)).toEqual([[1]]);
+  });
+});