@@ -1,4 +1,3 @@
 + stack
-+ next greater element
 + postfix evaluation
-+ balanced parentheses
++ balanced parentheses
@@ -0,0 +1,23 @@
+function nextGreaterElement(arr) {
+    stack = [];
+    res = Array(arr.length);
+    for (var i = 0; i < arr.length; i++) {
+        curr = arr[i];
+        while (stack.length && curr > arr[stack[stack.length - 1]]) {
+            res[stack.pop()] = curr;
+        }
+        stack.push(i);
+    }
+
+    while (stack.length) {
+        res[stack.pop()] = -1;
+    }
+
+    return res;
+}
+
+console.debug(nextGreaterElement([13, 7, 6, 12])); // [-1, 12, 12, -1]
+console.debug(nextGreaterElement([])); // []
+console.debug(nextGreaterElement([2, 3, 999])); // [3, 999, -1]
+console.debug(nextGreaterElement([5, 4, 3, 2, 1])); // [-1, -1, -1, -1, -1]
+console.debug(nextGreaterElement([1, 2, 3, 4, 5])); // [2, 3, 4, 5, -1]