Update monotonic-array.cpp

Author: kamyu104

C++/monotonic-array.cpp

@@ -5,7 +5,7 @@ class Solution {
 public:
     bool isMonotonic(vector<int>& A) {
         bool inc = false, dec = false;
-        for(int i = 0; i + 1 < A.size(); ++i) {
+        for (int i = 0; i + 1 < A.size(); ++i) {
             if (A[i] < A[i + 1]) {
                 inc = true;
             } else if (A[i] > A[i + 1]) {