Intersection Study - Algorithm(Search)

ALGORITHM

ALGORITHMSEARCH

ALGORITHM

SEARCH INTRO

What is Search?

ALGORITHM

SEARCH INTRO

1 3 4 6 7 8 10 13 14

When Dataset is Sorted

ALGORITHM

SEARCH INTRO

Binary Search

ALGORITHM

SEARCH INTRO

Dataset not Sorted

4 3 8 6 7 13 10 14 9

ALGORITHM

SEARCH INTRO

Search Process can Produce additional Data

4 3 8

6

7 13 10 14 9

1 11

3

ALGORITHM

SEARCH INTRO

State space Tree

ALGORITHM

SEARCH INTRO

Three Things to Decide

STATE STRUCTURE

SEARCH ORDER

ENDCONDITION

ALGORITHM

SEARCH DFS

DEPTHFIRST

SEARCH

ALGORITHM

SEARCH DFS

S

E

Is there way out?

ALGORITHM

SEARCH DFS

S

E

Is there way out?

STATE STRUCTURE

x y

ALGORITHM

SEARCH DFS

S

E

Is there way out?

SEARCHORDER

DFS

ALGORITHM

SEARCH DFS

S

E

Is there way out?

ENDCONDITION

(X,Y) = E

ALGORITHM

SEARCH DFS

S

E

Is there way out?

S

ALGORITHM

SEARCH DFS

S

E

Is there way out?

S

1,2

ALGORITHM

SEARCH DFS

S

E

Is there way out?

S

1,2

2,2

ALGORITHM

SEARCH DFS

S

E

Is there way out?

S

1,2

2,2

3,2

ALGORITHM

SEARCH DFS

S

E

Is there way out?

S

1,2

2,2

3,2

3,3

ALGORITHM

SEARCH DFS

S

E

Is there way out?

3,3

3,4

ALGORITHM

SEARCH DFS

S

E

Is there way out?

3,3

3,4

3,5

ALGORITHM

SEARCH DFS

S

E

Is there way out?

3,3

3,4

3,5

4,5

ALGORITHM

SEARCH DFS

S

E

Is there way out? YES

3,3

3,4

3,5

4,5

E

ALGORITHM

SEARCH DFS

S

E

Is there way out? YES

S

1,2

2,2

3,2

3,3

2,1

ALGORITHM

SEARCH DFS

Simple DFS prototype logic

function start

EndCondition

child function call

child function call

…

Return

ALGORITHM

SEARCH DFS

function start

EndCondition

Child function call

child function call

…

Return (x,y)==E or found

process(x+1,y)

process(x,y+1)

process(x-1,y)

process(x,y-1)

Simple DFS prototype logic

ALGORITHM

SEARCH DFS

Simple DFS prototype logic

loop start(Every possible start Node)

function

loop end condition

Search Complete

ALGORITHM

SEARCH DFS

Simple DFS prototype code

ALGORITHM

SEARCH BFS

BREADTHFIRST

SEARCH

ALGORITHM

SEARCH BFS

S

E

How many Shortest Path to End?

ALGORITHM

SEARCH BFS

S

E

How many Shortest Path to End?

STATE STRUCTURE

x ystep

ALGORITHM

SEARCH BFS

S

E

SEARCHORDER

BFS

How many Shortest Path to End?

ALGORITHM

SEARCH BFS

S

E

ENDCONDITION

(X,Y) = E

How many Shortest Path to End?

ALGORITHM

SEARCH BFS

S

E

How many Shortest Path to End?

S

1,1,2

ALGORITHM

SEARCH BFS

How many Shortest Path to End?

S

1,1,2 1,2,1

S

E

ALGORITHM

SEARCH BFS

How many Shortest Path to End?

S

1,1,2 1,2,1

S

E

2,2,2

ALGORITHM

SEARCH BFS

How many Shortest Path to End?

S

1,1,2 1,2,1

S

E

2,2,2 2,2,2

ALGORITHM

SEARCH BFS

How many Shortest Path to End?

S

1,1,2 1,2,1

S

E

2,2,2 2,2,2

2,3,2 2,3,2

ALGORITHM

SEARCH BFS

How many Shortest Path to End?

S

1,1,2 1,2,1

S

E

2,2,2 2,2,2

3,3,2 3,3,2

4,4,2 4,3,3 4,4,2 4,3,3

ALGORYTHM

SEARCH BFS

How many Shortest Path to End?

S

E

4,4,2 4,3,3

5,5,25,4,3 4,4,35,3,45,4,1

ALGORITHM

SEARCH BFS

How many Shortest Path to End?

S

E

4,4,2 4,3,3

5,5,25,4,3 5,4,35,3,45,4,1

6,4,3

ALGORITHM

SEARCH BFS

How many Shortest Path to End?

S

E

4,4,2 4,3,3

5,5,25,4,3 5,4,35,3,45,4,1

6,4,3

7,3,57,4,5

ALGORITHM

SEARCH BFS

How many Shortest Path to End? 8, 2

S

E

4,4,2 4,3,3

5,5,25,4,3 5,4,35,3,45,4,1

6,4,3

7,3,57,4,5

8,E 8,1,5

ALGORITHM

SEARCH BFS

Simple BFS prototype logic

loop start

EndCondition

Enqueue Start Node

Search Complete

Dequeue

Process

ALGORITHM

SEARCH BFS

Simple BFS prototype logic

loop start

EndCondition

Enqueue Start Node

Queue process end

Dequeue

Process

queue is Empty & found

1 2 3 4 5

Process

ALGORITHM

SEARCH BFS

Simple BFS prototype logic

process start

Enqueuecondition

enqueue

Enqueue loop start

Make new node

process end

ALGORITHM

SEARCH BFS

Simple BFS prototype logic

process start

Enqueuecondition

enqueue

Enqueue loop start

Make new node

process end

1 2 3 4 5

Process

Visited? End of map?

n1 n2 n3 n4

n2 n4

n2n4

ALGORITHM

SEARCH BFS

Simple BFS prototype logic

loop start(Every possible start Node)

Queue Process

loop end condition

Search Complete

ALGORITHM

SEARCH BFS

queue for BFS(left), BFS prototype code(right)