From 5a4265d7dba45ac58de7f0487ec07c6b60f92cef Mon Sep 17 00:00:00 2001
From: yanglbme <szuyanglb@outlook.com>
Date: Tue, 11 Jul 2023 09:13:59 +0800
Subject: [PATCH] feat: add ts solution to lc problem: No.1911

No.1911.Maximum Alternating Subsequence Sum
---
 .../README.md                                 | 25 +++++++++++++++++++
 .../README_EN.md                              | 25 +++++++++++++++++++
 .../Solution.ts                               |  7 ++++++
 3 files changed, 57 insertions(+)
 create mode 100644 solution/1900-1999/1911.Maximum Alternating Subsequence Sum/Solution.ts

diff --git a/solution/1900-1999/1911.Maximum Alternating Subsequence Sum/README.md b/solution/1900-1999/1911.Maximum Alternating Subsequence Sum/README.md
index 2a3ae8de76e57..b3f944923382f 100644
--- a/solution/1900-1999/1911.Maximum Alternating Subsequence Sum/README.md	
+++ b/solution/1900-1999/1911.Maximum Alternating Subsequence Sum/README.md	
@@ -212,6 +212,31 @@ func max(a, b int) int {
 }
 ```
 
+### **TypeScript**
+
+```ts
+function maxAlternatingSum(nums: number[]): number {
+    const n = nums.length;
+    const f: number[] = new Array(n + 1).fill(0);
+    const g = f.slice();
+    for (let i = 1; i <= n; ++i) {
+        f[i] = Math.max(g[i - 1] + nums[i - 1], f[i - 1]);
+        g[i] = Math.max(f[i - 1] - nums[i - 1], g[i - 1]);
+    }
+    return Math.max(f[n], g[n]);
+}
+```
+
+```ts
+function maxAlternatingSum(nums: number[]): number {
+    let [f, g] = [0, 0];
+    for (const x of nums) {
+        [f, g] = [Math.max(g - x, f), Math.max(f + x, g)];
+    }
+    return g;
+}
+```
+
 ### **...**
 
 ```
diff --git a/solution/1900-1999/1911.Maximum Alternating Subsequence Sum/README_EN.md b/solution/1900-1999/1911.Maximum Alternating Subsequence Sum/README_EN.md
index 7cb56ff6d83dd..64d12bd2179bf 100644
--- a/solution/1900-1999/1911.Maximum Alternating Subsequence Sum/README_EN.md	
+++ b/solution/1900-1999/1911.Maximum Alternating Subsequence Sum/README_EN.md	
@@ -180,6 +180,31 @@ func max(a, b int) int {
 }
 ```
 
+### **TypeScript**
+
+```ts
+function maxAlternatingSum(nums: number[]): number {
+    const n = nums.length;
+    const f: number[] = new Array(n + 1).fill(0);
+    const g = f.slice();
+    for (let i = 1; i <= n; ++i) {
+        f[i] = Math.max(g[i - 1] + nums[i - 1], f[i - 1]);
+        g[i] = Math.max(f[i - 1] - nums[i - 1], g[i - 1]);
+    }
+    return Math.max(f[n], g[n]);
+}
+```
+
+```ts
+function maxAlternatingSum(nums: number[]): number {
+    let [f, g] = [0, 0];
+    for (const x of nums) {
+        [f, g] = [Math.max(g - x, f), Math.max(f + x, g)];
+    }
+    return g;
+}
+```
+
 ### **...**
 
 ```
diff --git a/solution/1900-1999/1911.Maximum Alternating Subsequence Sum/Solution.ts b/solution/1900-1999/1911.Maximum Alternating Subsequence Sum/Solution.ts
new file mode 100644
index 0000000000000..7dbb1c90a1ce6
--- /dev/null
+++ b/solution/1900-1999/1911.Maximum Alternating Subsequence Sum/Solution.ts	
@@ -0,0 +1,7 @@
+function maxAlternatingSum(nums: number[]): number {
+    let [f, g] = [0, 0];
+    for (const x of nums) {
+        [f, g] = [Math.max(g - x, f), Math.max(f + x, g)];
+    }
+    return g;
+}