Add solution #372

Author: JoshCrozier

Diff for: README.md

@@ -155,6 +155,7 @@
 350|[Intersection of Two Arrays II](./0350-intersection-of-two-arrays-ii.js)|Easy|
 367|[Valid Perfect Square](./0367-valid-perfect-square.js)|Easy|
 371|[Sum of Two Integers](./0371-sum-of-two-integers.js)|Medium|
+372|[Super Pow](./0372-super-pow.js)|Medium|
 374|[Guess Number Higher or Lower](./0374-guess-number-higher-or-lower.js)|Medium|
 383|[Ransom Note](./0383-ransom-note.js)|Easy|
 387|[First Unique Character in a String](./0387-first-unique-character-in-a-string.js)|Easy|

Diff for: solutions/0372-super-pow.js

@@ -0,0 +1,31 @@
+/**
+ * 372. Super Pow
+ * https://leetcode.com/problems/super-pow/
+ * Difficulty: Medium
+ *
+ * Your task is to calculate ab mod 1337 where a is a positive integer and b
+ * is an extremely large positive integer given in the form of an array.
+ */
+
+/**
+ * @param {number} a
+ * @param {number[]} b
+ * @return {number}
+ */
+var superPow = function(a, b) {
+  return helper(BigInt(a), BigInt(b.join('')), 1337n);
+};
+
+function helper(a, b, mod) {
+  let r = 1n;
+
+  while (b > 0n) {
+    if (b % 2n == 1) {
+      r = r * a % mod;
+    }
+    b >>= 1n;
+    a = a * a % mod;
+  }
+
+  return Number(r);
+};