When I interviewed for Facebook, I got this problem in my Phone Interview, I faced this problem.

The string is given and we can “shift” it each of its letter to its successive letter, for example: "abc" -> "bcd". We have to be keep "shifting" which forms the sequence:

We have been given a binary tree consisting of nodes with digit values.

We need to take in account of every possible root-to-leaf path.

Each of these path represent a number. We have to effectively return the total sum of all the number represented by each of these paths.


Given an integer array nums and an integer k, return the k most frequent elements. You may return the answer in any order.

This problem can be solved using Heap(Priority Queue), Hashtable, Hashmap.

As we see here, there are two methods.

Part -2

In this part, we are going to see the diagnosing out of memory issues and high I/O wait time!

Diagnosing High I/O Wait.

When you see high I/O wait, one of the first things to check whether the machine is using a lot of swap.

Since the hard drive is much slower…


When a host is unreachable, you can perform the troubleshooting steps discussed earlier until the host is reachable again.

But what if the network is slow? Let’s list out the issues.

DNS Issues

When DNS does has an issue, it can often result in poor network performance. For example, if there…

Part -1

System load average is probably the most fundamental metric you start from when troubleshooting a sluggish system. One of the first commands that are commonly used when troubleshooting a slow system is uptime.

The three numbers after load average — 2.03, 20.17, and 15.09 …

Approaching Network Issues?

Network issues are the most common issues that have to be debugged with infrastructure and operations tasks.

Let’s take an example that, we have to debug an issue about the incoming traffic in NAT Box! How will you approach this issue?

Generally what are the steps will you be coming…

Explain DNS Load Balancing in simple way!

The main concept behind DNS Load Balancing is to distribute the traffic to different servers with the assistance of DNS Servers. In this the DNS Query resolves to multiple IP Addresses in random order.

To Note, there are total of 13 Root Server…

Take an example where you have been given a simple input form where you have to post a username which sends to the database and it replies with the results.

This code will append the content of “content.html” to the #results element.

This code is the explanation for how to send POST Data and output the Result.!

Explanation with HTML File

Assume you have an HTML file like this.

This is the example script for getting the Username for GET Call.

Balaji MJ

I write about Python, Algorithmic Trading, Quantitative Finance, and our Mind and Universe.

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