The answer has such pattern:

if nums.length == 1 ------ first-element itself.

if nums.length == 2 ------ first-element / second-element.

if nums.length > 2 ------ first-element / ( the other elements, separated by '/' ) , no matter what.

```
public class Solution {
public String optimalDivision(int[] nums) {
String str = "";
if(nums.length == 0){
return str;
}
str = str + nums[0];
if(nums.length == 1){
return str;
}
str = str + "/";
if(nums.length == 2){
return str + nums[1];
}
str = str + "(" + nums[1];
for(int i = 2; i < nums.length; i++){
str = str + "/" + nums[i];
}
str = str + ")";
return str;
}
}
```