Create neither-minimum-nor-maximum.cpp

Author: kamyu104

C++/neither-minimum-nor-maximum.cpp

@@ -0,0 +1,42 @@
+// Time:  O(n)
+// Space: O(1)
+
+// one pass, array
+class Solution {
+public:
+    int findNonMinOrMax(vector<int>& nums) {
+        int mx = numeric_limits<int>::min(), mn = numeric_limits<int>::max();
+        int result = -1;
+        for (const auto& x : nums) {
+            if (mn < x && x < mx) {
+                return x;
+            }
+            if (x < mn) {
+                result = mn;
+                mn = x;
+            }
+            if (x > mx) {
+                result = mx;
+                mx = x;
+            }
+        }
+        return mn < result && result < mx ? result : -1;
+    }
+};
+
+// Time:  O(n)
+// Space: O(1)
+// array
+class Solution2 {
+public:
+    int findNonMinOrMax(vector<int>& nums) {
+        const auto& mx = *max_element(cbegin(nums), cend(nums));
+        const auto& mn = *min_element(cbegin(nums), cend(nums));
+        for (const auto& x : nums) {
+            if (mn < x && x < mx) {
+                return x;
+            }
+        }
+        return -1;
+    }
+};