Create diet-plan-performance.cpp

Author: kamyu104

C++/diet-plan-performance.cpp

@@ -0,0 +1,15 @@
+// Time:  O(n)
+// Space: O(1)
+
+class Solution {
+public:
+    int dietPlanPerformance(vector<int>& calories, int k, int lower, int upper) {
+        int total = accumulate(calories.cbegin(), calories.cbegin() + k, 0);
+        int result = int(total > upper) - int(total < lower);
+        for (int i = k; i < calories.size(); ++i) {
+            total += calories[i] - calories[i - k];
+            result += int(total > upper) - int(total < lower);
+        }
+        return result;
+    }
+};