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Given an array nums. We define a running sum of an array as runningSum[i] = sum(nums[0]…nums[i]).

Return the running sum of nums.

Example 1:

Example 2:

Example 3:


  • 1 <= nums.length <= 1000
  • -10^6 <= nums[i] <= 10^6


Write a function to find the longest common prefix string amongst an array of strings.

If there is no common prefix, return an empty string "".

Example 1:

Example 2:


  • 0 <= strs.length <= 200
  • 0 <= strs[i].length <= 200
  • strs[i] consists of only lower-case English letters.

Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.

You may assume that each input would have exactly one solution, and you may not use the same element twice.

You can return the answer in any…

Understand the basic concepts of RDS, the benefits of using it compared to a conventional database solution and the key features of our RDS.

Without cloud, how set up a database?

  1. prepare hardware
  2. install operating system
  3. install database software
  4. tweaking

Conclusion: costly and it cost around 3 to 5 hours

With cloud, how set up a database?

  1. purchase a cloud server with desired OS…

Before talk about RESTFUL, we have to understand what is REST.

REST aka Representational State Transfer its a software architect develop by Prof Roy Fielding at 2000. It replace the old SOAP and became the new Web API standard.

what is Web API?

If we want get something from a website, we access the…

The China based payments company Ant Financial, which belong to AliPay had start to acquire digital wallet in South East Asia by joint venture with the local digital wallet.

  • Touch’n Go eWallet in Malaysia
  • eMoneky in Vietnam
  • DANA in Indonesia
  • GCash in Philippine
  • Kakaopay in Korea
  • and more

So how…

In system architecture, each level have their own define object type. Here will briefly explain each of the level object using the most simple and understandable scenario.

Level 1: VO — value object

VO is the UI level object in a system. It used to display the UI object values.

Level 2: DTO — data transfer object

DTO, client side object that expose…


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