Create maximum-alternating-subsequence-sum.cpp

Author: kamyu104

C++/maximum-alternating-subsequence-sum.cpp

@@ -0,0 +1,13 @@
+// Time:  O(n)
+// Space: O(1)
+
+class Solution {
+public:
+    long long maxAlternatingSum(vector<int>& nums) {
+        long long result = nums[0];
+        for (int i = 0; i < size(nums) - 1; ++i) {
+            result += max(nums[i + 1] - nums[i], 0);
+        }
+        return result;
+    }
+};