Create 941. Valid Mountain Array.cpp

Author: fengvyi

C++/941. Valid Mountain Array.cpp

@@ -0,0 +1,19 @@
+class Solution {
+public:
+    bool validMountainArray(vector<int>& A) {
+        int i = 0, n = A.size();
+        if (n < 3) {
+            return false;
+        }
+        while (i < n - 1 && A[i] < A[i + 1]) {
+            ++i;
+        }
+        if (i == 0 || i == n - 1) {
+            return false;
+        }
+        while (i < n - 1 && A[i] > A[i + 1]) {
+            ++i;
+        }
+        return i == n - 1;
+    }
+};