## Basic things for Motivation/ First Essential talk
**Importance of Small Difference**
- Example 1 :
- Ask about Breaking Bad
- discuss the importance of extra 3% clear crystals that walter white made
- Example 2 :
- show Pictures of fastest man in India , Asia , World
- discuss the impact of small millisec difference in timings
- Depict it with the equation - ``` (1.01)^365 = 37.78 ```
**Qualities Essential to be the Best**
- Ask about some essential qualities needed
- Discuss the importance of few -
- Consistency
- Persistance
- Hardwork in right direction
- The will power
**Performace Equation**
- Discuss about the Performace Equation - ``` Performance = Potential - interference ```
- why the potential should be increased and interference should be decreased
- How can the performance be enhanced
- Attend All Classes
- Be Mindful
- **Learning is important**
## Many technologies, Where to start from?
- discuss about multiple technologies available , maybe ask students about some names
- frontend - js,react , angular , vue etc
- backend - java , python , ruby etc
- Machine Learning
- introduce Data structures and Algorithms
- define and differentiate
- Data Structure - Something we need to organise data / keep data / Store data
= Algorithms - the process / the steps
- give an example of toothbrush being placed in kitchen
- discuss about the importance of Data structures and Algorithms
- Eventually reach to the conclusion that Data structure and Algorithms are important
## Building a site more important than learning about Data Structures and Algorithms ?**
- Ask the question and then discuss the result with examples
- Example 1 : **E-Commerce**
- Dicuss the flow from searching a product to buying it
- Discuss why we need Data structures and Algorithms in following functionalities
- Searching a Product - need to be fast
- Sorting - basis of price , category , reviews etc
- Search typeahead - throw the name of **trie** just to introduce a wow-factor
- Concurrency problem - 1 product , 2 buyers
- Eventually convince that DSA is more important than just building a site
- Example 2 : **Food Delivery**
- Finding nearest restaurant
- Sorting the list of restaurant - basis of name , reviews , location
- **Utilisation of resources** (Explain with the help of diagram)
- Shortest path of delivery
- Shortest time is another factor to consider
- more factors which finally helps in better utilisation of resources
- Ask if it's now clear that DSA is the basic building block
## How Problem Solving works?
- Dicuss about the computer and decision making
- How the computer doesn't have mind of its own
- How every step needed to be told to computer based on several decisions
- Example 1 : **ATM Machine**
- Discuss the process outline
- Discuss the process in detail using decision tree (Don't introduce the name yet)
- after drawing a basic decision tree - introduce with the name "Decision Tree"
- Keep on focusing on the importance of decisions in problem solving
- Example 2 : **Super Mario**
- Engage students by asking about the game
- Discuss what decision making happend when you press ```->``` arrow
- Example 3 : **Pubg Game**
- Engage students by asking about the game
- Discuss what decision making happens while a person shoots in pubg
- How does energy/health reduction happens , what are different variables involved to make one decision
- Aim
- Distance
- Type of Gun
- Body Armor
## "Observation" - The key to solve Problems
- Discuss about Guass
- Ask students if they know about him, what they know
- state the problem - tell them his teacher gave him the problem
- Problem : Find the sum of numbers from 1 -> 100
- discuss that He didn't jump on problem directly, **made observation** (focus on observation)
- **Prime Numbers**
- What are prime Numbers
- why 1 and 0 are not prime
- Given a number check if it's prime or not - ask students for the solution
- Approach 1 : Iterate from 1 -> N and check if it is divisble or not
- Approach 2 : Sqaure root approach - traverse only till square root
- Intution - factors always occurs in pairs - focus on presenting it as an observation
- give proof by examples
- Time analysis between O(N) and O(squareRoot(N))
- Considering one % (mod operation - ask if they know) takes 1 msec
N | Approach 1 - N steps | Approach 2 - sqaureRoot(N) steps
-- | -------------------- | --------------------------------
11 | 11 msec | 3 msec
101 | 101 msec | 10 msec
100000 | 16.6 min | 1 sec
10^18 | 116 days | 1.66 min
- Ask them if they appreciate the improvement in timings - put more focus
- **Find sqaure root of a given Number**
- Explain the problem - have to find the integer part
- Approach - 1 :
- iterate i from 1 to N and check if square of i is <= N
- if square <= N - it is current ans
- else stop the process - **WHY?** - Explain
- Ask if the Approach 1 is fast enough to increase the curiosity
- Approach - 2 :
- start by stating an observation
- pick some random element and check if it's square is <= or > than N
- based on previous checks decide to ignore one part - properly explain this with example
- now rather than picking random , pick middle element
- reason for picking middle element - it always removes atleast half of the prospect solution
- Discuss the time Analysis
## How Data Structures helps in Problem Solving?
- Discuss how just the way of organising the data can optimise the solution
- Give example of toothBrush , how toothbrush stored in kitchen would result in ineffeciency
- **Dictionary Word Search**
- Discuss the process of searching a word in dictionary
- Relation with the sqaure root problem
- Name of the Algorithm - Binary Search
- How are we able to apply the Binary Search
- Order matters (Main situation)
- Arrangement of Data Matters / Organisation of Data Matters
- **HC Verma** Example - searching a word in HC verma
- Why Binary search won't work
- No particular organisation of data
- Can sort all the words - But is it effecient ? NO!
- Discuss Index / Appendix
- How data is stored in a different way which improves efficency
word | page nos.
---- | ---------
velocity | 100 101 167
- Data Structure used - **Inverted Index**
- All search engines use this to optumise the search
## Conclusion
- Importance of Observation
- Importance of Data structures and Algorithms
- Importance of 3 essential qualities
- Further work