@@ -0,0 +1,41 @@
+1 <= A.length <= 50000
+-100000 <= A[i] <= 100000
+*/
+
+/**
+ * @param {number[]} A
+ * @return {boolean}
+ */
+var isMonotonic = function(A) {
+    if(A.length <= 2){
+      return true;
+    }
+    let lensA = A.length;
+    let isBig;
+    let pos;
+    for(let i = 0; i < lensA - 1; i++){
+      if(A[i]!== A[i+1]){
+        isBig = A[i] > A[i+1];
+        pos = i + 1;
+        break;
+      }
+    }
+    for(let i = pos; i < lensA - 1; i++){
+      if(isBig){
+        if(A[i] < A[i+1]){
+          return false;
+        }
+      }else{
+        if(A[i] > A[i+1]){
+          return false;
+        }
+      }
+    }
+    return true;
+};
+
+
+/**
+ * Runtime: 76 ms, faster than 60.83% of JavaScript online submissions for Monotonic Array.
+Memory Usage: 40.3 MB, less than 77.78% of JavaScript online submissions for Monotonic Array
+ */