Graphs
CIS 675
Map Coloring
Suppose you are trying to pick colors for a map.
If two countries are next to each other, they
should have dierent colors.
How do you pick the colors?
CIS 675
Sor0g
CIS 675
Sor0g Algorithms
Goal: Given an unsorted array, output a sorted
array.
CIS 675
Sor0g Algorithms
Goal: Given an unsorted array, output a sorted
array.
Main ques%ons:
Wor
Running Time Analysis
CIS 675
Why Analyze Running Time?
Suppose youve created a new algorithm.
How do you convince people to use it?
Does it
Run faster?
Use fewer resources?
CIS 675
Why A
Depth-First Search
CIS 675
Searches in Graphs
Suppose we are given a vertex u and we want
to nd all ver?ces v that are reachable from u
(i.e., there is a path from u to v).
CIS 675
Depth
Directed Acyclic Graphs
CIS 675
Directed Acyclic Graphs (DAGs)
A DAG is a directed graph without cycles.
How can you tell whether a directed graph has a
cycle?
CIS 675
Directed Acyclic Gr
Divide and Conquer
CIS 675
Overview
A divide-and-conquer algorithm has three main
steps:
1. Break the problem into smaller subproblems.
2. Recursively solve the subproblems.
3. Combine the
Recurrence Relations
CIS 675
Recurrence Relations
A recurrence relation is an equation that
recursively defines a functions values in terms
of earlier values.
It can be very useful for analyzing a
The Master Method
CIS 675
Bounding Recurrences: The Master Method
n
d),
Suppose T(n) = aT( ) + O(n
b
for a > 0, b > 1, d 0.
ceiling symbol:
means to round
up
Case 1: If d > logba, then
Proofs
CIS 675
CIS 675: How to Write a Proof
Is the sum of two even numbers even, odd, or possibly
either?
CIS 675: Design and Analysis of Algorithms
Proving a MathemaEcal Claim
There are sever
Building Java Programs
Chapter 15
testing ArrayIntList;
pre/post conditions and exceptions
reading: 4.4 15.1 - 15.3
2
Searching methods
Implement the following methods:
indexOf returns first index o
Applied Linear Algebra Refresher Course
Karianne Bergen
[email protected]
Institute for Computational and Mathematical Engineering,
Stanford University
September 16-19, 2013
K. Bergen
(ICME)
Applie
Nearest neighbors classifiers
James McInerney
Adapted from slides by Daniel Hsu
Sept 11, 2017
1 / 25
Housekeeping
I
We received 167 HW0 submissions on Gradescope before midnight Sept
10th.
I
From a ra
Building Java Programs
Chapter 10
ArrayList
reading: 10.1
Welcome to CSE 143!
2
Words exercise
Write code to read a file and display its words in reverse
order.
A solution that uses an array:
String
Building Java Programs
Chapter 15
Implementing ArrayIntList
reading: 15.1 - 15.3
2
Recall: classes and objects
class: A program entity that represents:
A complete program or module, or
A template f
Machine Learning (COMS 4771) Week 1
James McInerney
Adapted from slides by Daniel Hsu
Sept 6, 2017
1 / 22
About me
I
Adjunct Assistant Professor at Columbia University in the Department of
Computer Sc
COMS 4771 Lecture 4
1. K-D trees for nearest neighbor search.
2. Decision trees.
1 / 22
K-D trees for nearest
neighbor search
Tree structures for one-dimensional data
A data structure for fast NN sear
KD trees and decision trees
James McInerney
Adapted from slides by Nakul Verma
Scaling k-NN Classification
Finding the k closest neighbor takes time!
Need to keep all the training data around during
Software Implementation
CIS454
Week 10: Creating High Quality Code
Edmund Yu, PhD
Associate Professor
[email protected]
March 16 & 23, 2015
(Based on Code Complete, Steve McConnell, 2nd
Ed. Microsoft Press
Software Implementation
CIS454
Week 6: Design Patterns, Part 4
Edmund Yu, PhD
Associate Professor
[email protected]
February 16, 2015
References:
Design Patterns, Erich Gamma, et al., 1995,
Head-First Desi
Software Implementation
CIS454
Week 13: Code Improvements
Edmund Yu, PhD
Associate Professor
[email protected]
April 6, 2015
(Based on Code Complete, Steve McConnell, 2nd Ed.
Microsoft Press, 2004) , Chapt
Software Implementation
CIS454
Week 12: Variables & Statements
Edmund Yu, PhD
Associate Professor
[email protected]
March 30, 2015
(Based on Code Complete, Steve McConnell, 2nd Ed.
Microsoft Press, 2004) ,
Software Implementation
CIS454
Week 1: Overview
Edmund Yu, PhD
Associate Professor
[email protected]
January 12, 2015
1
What Is Software?
Computer programs and associated documentation
Software products
Software Implementation
CIS454
Week 3: Design Patterns, Part 1
Edmund Yu, PhD
Associate Professor
[email protected]
January 26, 2015
References:
Design Patterns, Erich Gamma, et al., 1995,
Head-First Desig
Software Implementation
CIS454
Week 5: Design Patterns, Part 3
Edmund Yu, PhD
Associate Professor
[email protected]
February 9, 2015
References:
Design Patterns, Erich Gamma, et al., 1995,
Head-First Desig
Software Implementation
CIS454
Week 4: Design Patterns, Part 2
Edmund Yu, PhD
Associate Professor
[email protected]
February 2, 2014
References:
Design Patterns, Erich Gamma, et al., 1995,
Head-First Desig
3.1 Task 1: SYN Flooding Attack
SYN flood is a form of DoS attack in which attackers send many SYN requests to a victims TCP port,
but the attackers have no intention to finish the 3-way handshake pro
Task 1.a: Problem# 01: Please use your own words to describe the
sequence of the library calls that are essential for sniffer programs. This
is meant to be a summary, not detailed explanation like the
3 Lab Tasks
3.1 Task 1: Encryption using different ciphers and modes
In this task, we will play with various encryption algorithms and modes. You can use the following
openssl enc command to encrypt/d