Add solution #7

Author: JoshCrozier

README.md

@@ -8,6 +8,7 @@
 |:---|:---|:---|
 1|[Two Sum](./0001-two-sum.js)|Easy|
 4|[Median of Two Sorted Arrays](./0004-median-of-two-sorted-arrays.js)|Hard|
+7|[Reverse Integer](./0007-reverse-integer.js)|Easy|
 27|[Remove Element](./0027-remove-element.js)|Easy|
 31|[Next Permutation](./0031-next-permutation.js)|Medium|
 36|[Valid Sudoku](./0036-valid-sudoku.js)|Medium|

solutions/0007-reverse-integer.js

@@ -0,0 +1,23 @@
+/**
+ * 7. Reverse Integer
+ * https://leetcode.com/problems/reverse-integer/
+ * Difficulty: Easy
+ *
+ * Given a signed 32-bit integer x, return x with its digits reversed.
+ * If reversing x causes the value to go outside the signed 32-bit integer
+ * range [-2^31, 2^31 - 1], then return 0.
+ */
+
+/**
+ * @param {number} x
+ * @return {number}
+ */
+var reverse = function(x) {
+  const reversed = String(Math.abs(x)).split('').reverse().join('');
+
+  if (reversed > Math.pow(2, 31)) {
+    return 0;
+  }
+
+  return reversed * Math.sign(x);
+};