Added UglyNumber dynamic programming in java

java/Dynamic Programming/UglyNumber.java

@@ -0,0 +1,42 @@
+import java.util.Scanner;
+
+public class UglyNumber {
+    public static int helper_ugly(int n){
+        int[] ugly=new int[n+1];
+        ugly[0]=1;
+        int i2=0,i3=0,i5=0;
+        int next_multiple_2=2;
+        int next_multiple_3=3;
+        int next_multiple_5=5;
+        int next_num=1;
+        for(int i=1;i<n;i++)
+        {
+            next_num=Math.min(next_multiple_2,Math.min(next_multiple_3,next_multiple_5));
+            ugly[i]=next_num;
+            if(next_num==next_multiple_2)
+            {
+                i2++;
+                next_multiple_2=ugly[i2]*2;
+            }
+            if(next_num==next_multiple_3)
+            {
+                i3++;
+                next_multiple_3=ugly[i3]*3;
+            }
+            if(next_num==next_multiple_5)
+            {
+                i5++;
+                next_multiple_5=ugly[i5]*5;
+            }
+        }
+
+        return next_num;
+    }
+    public static void main(String args[])
+    {
+        Scanner sc=new Scanner(System.in);
+        int n=sc.nextInt();
+        System.out.println(helper_ugly(n));
+
+            }
+}