CSS106 Introduction to Elementary

AlgorithmsM.Sc Askar Satabaldiyev

What is an “algorithm”?

algorithm(noun):a set of steps

to accomplish a task

•Go to bus station

•Go to bus station• Take a bus

•Go to bus station• Take a bus•Go to university

•Go to bus station• Take a bus•Go to university (!)

• Slice bread

• Slice bread•Apply cheese

• Slice bread•Apply cheese•Get your cheese toast

Computer Science algorithms

Start with an input data

Start with an input data

Do complex calculations

Start with an input data

Do complex calculations

Stop when we find answer

Computer Science

a few examples…

Compression algorithms

Finding optimal route algorithms

rendering algorithms

Optimization and scheduling algorithms

Which algorithms will you use?

Make your programs

FASTER

Which algorithms could you CREATE?

Big Data Analysis

What makes a good algorithm?

What makes a good algorithm?

1. Correctness

2. Efficiency

Asymptotic Analysis

#nodes Nearest insertion

Brute force

1 1 1

2 4 1

3 9 2

4 16 6

…

25 625 620448401733239439360000

N2 N!

k = 0;for (i = 1; i <= N; i++) if (N % i == 0) k++;

return k == 2;

for (i = 2; i < n; i++) if(N % i == 0) return false;return true;

another method…

for (i = 2; i < sqrt(n); i++) if(N % i == 0) return false;return true;

Which one is faster?

Grading Policy

Attendance 10%Midterm Exam 20%Assignment 15%Homework 15%Quizes 10%Final Exam 30%Contests/Codeforces/Bonus 20%Total 100%(+20?)

Grading Policy

Intro to algorithms 01.Sept – 04.SeptBinary Search/Asymptotic notations

07.Sept – 11.Sept

Selection sort/Insertion sort 15.Sept – 18.SeptRecursive algorithms 22.Sept – 25.SeptTowers of Hanoi/Merge Sort/Quick sort

29.Sept – 02.OctGraph Representation 05.Oct – 09.OctBreadth-first search 12.Oct – 16.OctMidterm Exam 19.Oct – 23.Oct

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