---
# System prepended metadata

title: "\n\n\n\n"

---

```# System Design question area

# long url
https://www.addgene.org/pooled-library/morris-lab-celltag/

# short url
https://www.addgene.org/ab1s3eef2

# base domain name that should stay consistent
https://www.addgene.org/



```

```java


// time  O(N)
// sapce  O(N)

list1 = [1,2,3]
list2 = [1,1,1]
public static List<Integer> getCommon(int[] list1, int[] list2) {
    
    int n1 = list1.length;
    int n2 = list2.length;
    
    Set<Integer> set = new HashSet<>();
    
    // O(N)
    for (int i = 0; i < n1; i++) {
        set.add(list1[i]);
    }
    
    
    Set<Integer> set2 = new HashSet<>();

    
    // O(N)
    for (int i = 0; i < n2; i++) {
        
        // O(1)
        if (set.contains(list2[i])) {
            set2.add(list2[i]);
        }
    }
    
    List<Integer> result = new ArrayList<>(); 
    
    for (Integer element : set2) {
        result.add(element);
    }
    
    
    return result;
}
```


``` Database Design Question



table name : Order

OrderID: String, Primary key
Name   varchar(20)








Shipping_Street    varchar(20)
Shipping_City      varchar(20)
Shipping_state    varchar(2)        CA, MA, ME,          ABC
Shipping_zip_code varchar(5)         04103


add 


requirement :  search the shipping address which is in Maine


select *

from  XX table

where Shipping_state = "ME"






```