Add solution #1201

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,176 LeetCode solutions in JavaScript
+# 1,177 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -926,6 +926,7 @@
 1191|[K-Concatenation Maximum Sum](./solutions/1191-k-concatenation-maximum-sum.js)|Medium|
 1192|[Critical Connections in a Network](./solutions/1192-critical-connections-in-a-network.js)|Hard|
 1200|[Minimum Absolute Difference](./solutions/1200-minimum-absolute-difference.js)|Easy|
+1201|[Ugly Number III](./solutions/1201-ugly-number-iii.js)|Medium|
 1206|[Design Skiplist](./solutions/1206-design-skiplist.js)|Hard|
 1207|[Unique Number of Occurrences](./solutions/1207-unique-number-of-occurrences.js)|Easy|
 1208|[Get Equal Substrings Within Budget](./solutions/1208-get-equal-substrings-within-budget.js)|Medium|

solutions/1201-ugly-number-iii.js

@@ -0,0 +1,50 @@
+/**
+ * 1201. Ugly Number III
+ * https://leetcode.com/problems/ugly-number-iii/
+ * Difficulty: Medium
+ *
+ * An ugly number is a positive integer that is divisible by a, b, or c.
+ *
+ * Given four integers n, a, b, and c, return the nth ugly number.
+ */
+
+/**
+ * @param {number} n
+ * @param {number} a
+ * @param {number} b
+ * @param {number} c
+ * @return {number}
+ */
+var nthUglyNumber = function(n, a, b, c) {
+  const ab = lcm(a, b);
+  const bc = lcm(b, c);
+  const ac = lcm(a, c);
+  const abc = lcm(ab, c);
+  let left = 1;
+  let right = 2 * 10**9;
+
+  while (left < right) {
+    const mid = left + Math.floor((right - left) / 2);
+    if (countUgly(mid) < n) {
+      left = mid + 1;
+    } else {
+      right = mid;
+    }
+  }
+
+  return left;
+
+  function lcm(x, y) {
+    return (x * y) / gcd(x, y);
+  }
+
+  function gcd(x, y) {
+    return y === 0 ? x : gcd(y, x % y);
+  }
+
+  function countUgly(num) {
+    return Math.floor(num / a) + Math.floor(num / b) + Math.floor(num / c)
+      - Math.floor(num / ab) - Math.floor(num / bc) - Math.floor(num / ac)
+      + Math.floor(num / abc);
+  }
+};