Create array-nesting.cpp

Author: kamyu104

Diff for: C++/array-nesting.cpp

@@ -0,0 +1,22 @@
+// Time:  O(n)
+// Space: O(1)
+
+class Solution {
+public:
+    int arrayNesting(vector<int>& nums) {
+        auto result = 0;
+        for (const auto& num : nums) {
+            if (num != numeric_limits<int>::max()) {
+                auto start = num, count = 0;
+                while (nums[start] != numeric_limits<int>::max()) {
+                    auto temp = start;
+                    start = nums[start];
+                    nums[temp] = numeric_limits<int>::max();
+                    ++count;
+                }
+                result = max(result, count);
+            }
+        }
+        return result;
+    }
+};