Feat | NeetCode | Roadmap | #15 Best Time To Buy And Sell Stock

README.md

@@ -84,4 +84,6 @@
   - [Task #11](src/neetcode/two-pointers/two-sum-ii-input-array-is-sorted) - _Two Sum II Input Array Is Sorted_ - _[check the task](https://neetcode.io/problems/two-integer-sum-ii)_
   - [Task #12](src/neetcode/two-pointers/3sum) - _3Sum_ - _[check the task](https://neetcode.io/problems/three-integer-sum)_
   - [Task #13](src/neetcode/two-pointers/container-with-most-water) - _Container With Most Water_ - _[check the task](https://neetcode.io/problems/max-water-container)_
-  - [Task #14](src/neetcode/two-pointers/trapping-rain-water) - _Trapping Rain Water_ - _[check the task](https://neetcode.io/problems/trapping-rain-water)_
+  - [Task #14](src/neetcode/two-pointers/trapping-rain-water) - _Trapping Rain Water_ - _[check the task](https://neetcode.io/problems/trapping-rain-water)_
+- Sliding Window
+  - [Task #15](src/neetcode/sliding-window/best-time-to-buy-and-sell-stock) – _Best Time To Buy And Sell Stock_ - _[check the task](https://neetcode.io/problems/buy-and-sell-crypto)_

src/neetcode/sliding-window/best-time-to-buy-and-sell-stock/solution.test.ts

@@ -0,0 +1,15 @@
+import { maxProfit } from './solution';
+
+describe('Best Time To Buy And Sell Stock | NeetCode RoadMap | Testcases', () => {
+  test('#1 Buy on day 2, sell on day 5', () => {
+    const prices = [10, 1, 5, 6, 7, 1];
+    const output = maxProfit(prices);
+    expect(output).toBe(6);
+  });
+
+  test('#2 No buy, no sell', () => {
+    const prices = [10, 8, 7, 5, 2];
+    const output = maxProfit(prices);
+    expect(output).toBe(0);
+  });
+});

src/neetcode/sliding-window/best-time-to-buy-and-sell-stock/solution.ts

@@ -0,0 +1,21 @@
+/**
+ * @param {number[]} prices - an integer array, where `prices[i]` is the price of NeetCoin on the `ith` day.
+ * @return {number} - the maximum profit that can be achieved.
+ */
+export const maxProfit = (prices: number[]): number => {
+  let l = 0;
+  let r = 1;
+  let mxProfit = 0;
+
+  while (r < prices.length) {
+    if (prices[l] < prices[r]) {
+      const profit = prices[r] - prices[l];
+      mxProfit = Math.max(mxProfit, profit);
+    } else {
+      l = r;
+    }
+    r++;
+  }
+
+  return mxProfit;
+};