Added Largest Number.java

Author: varunu28

Medium/Largest Number.java

@@ -0,0 +1,10 @@
+class Solution {
+  public String largestNumber(int[] nums) {
+    String largestNum = Arrays.stream(nums)
+        .boxed()
+        .map(String::valueOf)
+        .sorted((o1, o2) -> (o2 + o1).compareTo(o1 + o2))
+        .collect(Collectors.joining(""));
+    return largestNum.charAt(0) == '0' ? "0" : largestNum;
+  }
+}