update the docs

Author: realdennis

readme.md

@@ -1,16 +1,20 @@
-# leetcode-typescript
+# leetcode-ts
 
-Collection of my leetcode prob solution.
+Collection of leetcode prob solutions using TypeScript.
 
-## How to Run it
+## How to use it?
+
+Type "T", in this repo page, and then type the problem title like "best-time-to-buy-and-sell-stock".
+
+And you'll see that file `best-time-to-buy-and-sell-stock.ts` is under the `src/kadanes-algorithm` it's the related topic of this prob, then enter and see the solution, some solution I've added the thinking process as comment.
+
+## How to Run it?
 
 ```
 $ npm i # install dependency, typescript, ts-node
 $ npx ts-node src/rotate-array.ts
 ```
 
-Don't forget to add the test case if you really wanna run it.
-
-Most use case might just reference...
+Don't forget to add the test case if you really want to run it!
 
-I would try to sort of by topic (like backtracking / binary search / idk)
+Most use-case of this repo might be just a reference.

src/backtracking/surrounded-regions.ts

@@ -9,42 +9,32 @@ function solve(board: string[][]): void {
 
     let collection: number[][] = [];
     let isBorder = false;
-    const dfs = (pos: number[]): void => {
-        const [x, y] = pos;
-        if (x < 0 || y < 0 || x >= M || y >= N) return;
-        if (visited[x][y]) return;
-        if (board[x][y] === "X") return;
+    const dfs = (i: number, j: number): void => {
+        if (i < 0 || j < 0 || i >= M || j >= N) return;
+        if (visited[i][j]) return;
+        if (board[i][j] === "X") return;
 
-        visited[x][y] = true;
-        collection.push([x, y]);
-        if (x === 0 || y === 0 || x === M - 1 || y === N - 1) {
+        visited[i][j] = true;
+        collection.push([i, j]);
+        if (i === 0 || j === 0 || i === M - 1 || j === N - 1) {
             isBorder = true;
         }
-        dfs([x - 1, y]);
-        dfs([x + 1, y]);
-        dfs([x, y - 1]);
-        dfs([x, y + 1]);
+        dfs(i - 1, j);
+        dfs(i + 1, j);
+        dfs(i, j - 1);
+        dfs(i, j + 1);
     };
 
     for (let i = 0; i < M; i++) {
         for (let j = 0; j < N; j++) {
             collection = [];
             isBorder = false;
-            dfs([i, j]);
+            dfs(i, j);
             if (isBorder) continue;
-            for (let col of collection) {
-                const [x, y] = col;
+            for (let pos of collection) {
+                const [x, y] = pos;
                 board[x][y] = "X";
             }
         }
     }
 }
-
-const q = [
-    ["X", "X", "X", "X"],
-    ["X", "O", "O", "X"],
-    ["X", "X", "O", "X"],
-    ["X", "O", "X", "X"],
-];
-solve(q);
-console.log(q);

src/kadanes-algo/best-time-to-buy-and-sell-stock.ts

@@ -12,8 +12,8 @@ function containsNearbyAlmostDuplicate(nums: number[], k: number, t: number): bo
         const key = getBucketKey(cur);
         return (
             bucket.has(key) ||
-            (bucket.has(key + 1) && bucket.get(key + 1) - cur <= t) ||
-            (bucket.has(key - 1) && cur - bucket.get(key - 1) <= t)
+            (bucket.has(key + 1) && bucket.get(key + 1)! - cur <= t) ||
+            (bucket.has(key - 1) && cur - bucket.get(key - 1)! <= t)
         );
     };
 

src/slding-window/contain-duplicate-III.ts

@@ -10,7 +10,7 @@ class Trie {
         const rest = word.substring(1);
         if (!this.map.has(first)) this.map.set(first, new Trie());
 
-        this.map.get(first).insert(rest);
+        this.map.get(first)!.insert(rest);
     }
 
     search(word: string): boolean {
@@ -20,7 +20,7 @@ class Trie {
         const rest = word.substring(1);
 
         if (!this.map.has(first)) return false;
-        return this.map.get(first).search(rest);
+        return this.map.get(first)!.search(rest);
     }
 
     startsWith(prefix: string): boolean {
@@ -29,7 +29,7 @@ class Trie {
         const rest = prefix.substring(1);
 
         if (!this.map.has(first)) return false;
-        return this.map.get(first).startsWith(rest);
+        return this.map.get(first)!.startsWith(rest);
     }
 }