solves ugly numbr ii in java

Author: anishLearnsToCode

README.md

@@ -215,7 +215,7 @@
 | 260  | [Single Number III](https://leetcode.com/problems/single-number-iii)                                                                                      |                                                                 [![Java](assets/java.png)](src/SingleNumberIII.java)                                                                 |                                                                                                                                   |
 | 261  | 🔒 [Graph Valid Tree](https://leetcode.com/problems/graph-valid-tree)                                                                                     |                                                                                                                                                                                      |                                                                                                                                   |
 | 263  | [Ugly Number](https://leetcode.com/problems/ugly-number)                                                                                                  |                                        [![Java](assets/java.png)](src/UglyNumber.java) [![Python](assets/python.png)](python/ugly_number.py)                                         |                                                                                                                                   |
-| 264  | [Ugly Number II](https://leetcode.com/problems/ugly-number-ii)                                                                                            |                                                                                                                                                                                      |                                                                                                                                   |
+| 264  | [Ugly Number II](https://leetcode.com/problems/ugly-number-ii)                                                                                            |                                                                  [![Java](assets/java.png)](src/UglyNumberII.java)                                                                   |                                                                                                                                   |
 | 266  | 🔒 [Palindrome Permutation](https://leetcode.com/problems/palindrome-permutation)                                                                         |                                                                                                                                                                                      |                                                                                                                                   |
 | 267  | 🔒 [Palindrome Permutation II](https://leetcode.com/problems/palindrome-permutation-ii)                                                                   |                                                                                                                                                                                      |                                                                                                                                   |
 | 268  | [Missing Number](https://leetcode.com/problems/missing-number)                                                                                            |                                     [![Java](assets/java.png)](src/MissingNumber.java) [![Python](assets/python.png)](python/missing_number.py)                                      |                                                                                                                                   |

src/UglyNumberII.java

@@ -0,0 +1,27 @@
+// https://leetcode.com/problems/ugly-number-ii
+// T: O(N)
+// S: O(N)
+
+public class UglyNumberII {
+    public int nthUglyNumber(int n) {
+        final int[] dp = new int[n];
+        dp[0] = 1;
+        int index2, index3, index5;
+        index2 = index3 = index5 = 0;
+        int factor2 = 2, factor3 = 3, factor5 = 5;
+
+        for(int i = 1 ; i < n ; i++) {
+            final int uglyNumber = min(factor2, factor3, factor5);
+            dp[i] = uglyNumber;
+            if(factor2 == uglyNumber) factor2 = 2 * dp[++index2];
+            if(factor3 == uglyNumber) factor3 = 3 * dp[++index3];
+            if(factor5 == uglyNumber) factor5 = 5 * dp[++index5];
+        }
+
+        return dp[n-1];
+    }
+
+    private int min(int a, int b, int c) {
+        return Math.min(a, Math.min(b, c));
+    }
+}