248th Commit

README.md

@@ -252,12 +252,14 @@ Ace Coding Interview with 75 Qs
 [198]: ./src/page-2/198.%20House%20Robber/rob.ts
 [790]: ./src/page-8/790.%20Domino%20and%20Tromino%20Tiling/numTilings.ts
 
-| DP - Multidimensional                                     |          |        |
-| --------------------------------------------------------- | -------- | ------ |
-| 62. Unique Paths                                          | Solution | Medium |
-| 1143. Longest Common Subsequence                          | Solution | Medium |
-| 714. Best Time to Buy and Sell Stock with Transaction Fee | Solution | Medium |
-| 72. Edit Distance                                         | Solution | Medium |
+| DP - Multidimensional                                     |                |        |
+| --------------------------------------------------------- | -------------- | ------ |
+| 62. Unique Paths                                          | [Solution][62] | Medium |
+| 1143. Longest Common Subsequence                          | Solution       | Medium |
+| 714. Best Time to Buy and Sell Stock with Transaction Fee | Solution       | Medium |
+| 72. Edit Distance                                         | Solution       | Medium |
+
+[62]: ./src/page-1/62.%20Unique%20Paths/uniquePaths.ts
 
 | Bit Manipulation                              |                  |        |
 | --------------------------------------------- | ---------------- | ------ |
@@ -647,7 +649,7 @@ Must-do List for Interview Prep
 | ----------------------------------- | --------------- | ------ |
 | 5. Longest Palindromic Substring    | [Solution][5]   | Medium |
 | 32. Longest Valid Parentheses       | Solution        | Hard   |
-| 62. Unique Paths                    | Solution        | Medium |
+| 62. Unique Paths                    | [Solution][62]  | Medium |
 | 64. Minimum Path Sum                | Solution        | Medium |
 | 70. Climbing Stairs                 | [Solution][70]  | Easy   |
 | 72. Edit Distance                   | Solution        | Medium |
@@ -662,6 +664,7 @@ Must-do List for Interview Prep
 | 1143. Longest Common Subsequence    | Solution        | Medium |
 
 [5]: ./src/page-1/5.%20Longest%20Palindromic%20Substring/longestPalindrome.ts
+[62]: ./src/page-1/62.%20Unique%20Paths/uniquePaths.ts
 [70]: ./src/page-1/70.%20Climbing%20Stairs/climbStairs.ts
 [118]: ./src/page-2/118.%20Pascal's%20Triangle/generate.ts
 [198]: ./src/page-2/198.%20House%20Robber/rob.ts

src/page-1/62. Unique Paths/uniquePaths.test.ts

@@ -0,0 +1,8 @@
+import { uniquePaths } from './uniquePaths';
+
+describe('62. Unique Paths', () => {
+  test('uniquePaths', () => {
+    expect(uniquePaths(3, 7)).toBe(28);
+    expect(uniquePaths(3, 2)).toBe(3);
+  });
+});

src/page-1/62. Unique Paths/uniquePaths.ts

@@ -0,0 +1,22 @@
+type UniquePaths = (m: number, n: number) => number;
+
+/**
+ * Accepted
+ */
+export const uniquePaths: UniquePaths = (m, n) => {
+  const dp: number[][] = Array.from({ length: m }, () => Array(n).fill(0));
+
+  // Initialize the first row and first column
+  for (let i = 0; i < m; i++) dp[i][0] = 1;
+  for (let j = 0; j < n; j++) dp[0][j] = 1;
+
+  // Fill in the rest of the dp array
+  for (let i = 1; i < m; i++) {
+    for (let j = 1; j < n; j++) {
+      dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
+    }
+  }
+
+  // The bottom-right corner will contain the number of unique paths
+  return dp[m - 1][n - 1];
+};