Create maximum-sum-circular-subarray.cpp

Author: kamyu104

C++/maximum-sum-circular-subarray.cpp

@@ -0,0 +1,19 @@
+// Time:  O(n)
+// Space: O(1)
+
+class Solution {
+public:
+    int maxSubarraySumCircular(vector<int>& A) {
+        int total = 0;
+        int max_sum = numeric_limits<int>::min(), cur_max = 0;
+        int min_sum = numeric_limits<int>::max(), cur_min = 0;
+        for (const auto& a : A) {
+            cur_max = max(cur_max + a, a);
+            max_sum = max(max_sum, cur_max);
+            cur_min = min(cur_min + a, a);
+            min_sum = min(min_sum, cur_min);
+            total += a;
+        }
+        return max_sum > 0 ? max(max_sum, total - min_sum) : max_sum;
+    }
+};