Algorithm and Programming (Searching)
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The document presents an overview of searching algorithms, focusing on sequential and binary search methods. It details the processes for sequential search with and without sentinels as well as using boolean variables, and explains binary search with principles of dividing data into two parts. The document also includes pseudocode for each search method and contact information for the author.
![Ilustration of Seq. Search Without Sentinel
Given an array to be processed:
Number
Data that want to be sought : 9
• Number[1] = 9?
• Number[2] = 9?
• Number[3] = 9?
Result: 9 is found in number[3]
5 1 9 4 2
[1] [2] [3] [4] [5]
i i + 1
i i + 1
i (STOP SEARCH)](https://image.slidesharecdn.com/chapter11-searching-161018112309/85/Algorithm-and-Programming-Searching-9-320.jpg)
![Sequential Search Without Sentinel
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Procedure SeqSearchTanpaSentinel (Input nama_array:tipe_array)
{I.S. : elemen array [1..maks_array] sudah terdefinisi}
{F.S. : menampilkan hasil pencarian (ditemukan/tidak)}
Kamus:
i : integer
data_cari : tipedata
Algoritma:
input(data_cari)
i 1
while(nama_array [i] ≠ data_cari) and (i < maks_array) do
i i + 1
endwhile
if (nama_array[i] = data_cari)
then
output(data_cari,’ ditemukan pada indeks ke-’,i)
else
output(data_cari,’ tidak ditemukan’)
endif
EndProcedure](https://image.slidesharecdn.com/chapter11-searching-161018112309/85/Algorithm-and-Programming-Searching-10-320.jpg)
![Ilustration of Seq. Search Use Sentinel
Data that was sought: 9
Number
Result: Data was found in Number[3]
Data that was sought: 10
Number
Result: Data was not found
5 1 9 4 2 9
[1] [2] [3] [4] [5] [6]
sentinel
5 1 9 4 2 10
[1] [2] [3] [4] [5] [6]
sentinel](https://image.slidesharecdn.com/chapter11-searching-161018112309/85/Algorithm-and-Programming-Searching-12-320.jpg)
![Sequential Search Use Sentinel
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Procedure SeqSearchSentinel (Input nama_array:tipe_array)
{I.S. : elemen array [1..maks_array] sudah terdefinisi}
{F.S. : menampilkan hasil pencarian (ditemukan/tidak)}
Kamus:
i : integer
data_cari : tipedata
Algoritma:
input(data_cari)
i 1
nama_array(maks_array + 1) data_cari
while (nama_array [i] ≠ data_cari) do
i i + 1
endwhile
if (i < maks_array+1)
then
output(data_cari,’ ditemukan pada indeks ke-’,i)
else
output(data_cari,’ tidak ditemukan’)
endif
EndProcedure](https://image.slidesharecdn.com/chapter11-searching-161018112309/85/Algorithm-and-Programming-Searching-13-320.jpg)
![Ilustration of Seq. Search Use Boolean
Given an array to be processed:
Number
Data that want to be sought : 9
• Number[1] = 9?
• Number[2] = 9?
• Number[3] = 9?
Result: 9 is found in number[3]
5 1 9 4 2
[1] [2] [3] [4] [5]
FOUND FALSE
FOUND FALSE
FOUND TRUE (STOP SEARCH)](https://image.slidesharecdn.com/chapter11-searching-161018112309/85/Algorithm-and-Programming-Searching-15-320.jpg)
![Sequential Search Use Sentinel
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Procedure SeqSearchBoolean (Input nama_array:tipe_array)
{I.S. : elemen array [1..maks_array] sudah terdefinisi}
{F.S. : menampilkan data yg dicari ditemukan atau tidak ditemukan}
Kamus:
i : integer
ketemu : boolean
data_cari : tipedata
Algoritma:
input(data_cari)
i 1
ketemu false
while (not ketemu) and (i ≤ maks_array) do
if(nama_var_array(i) = data_cari)
then
ketemu true
else
i i + 1
endif
endwhile
if (ketemu)
then
output(data_cari,’ ditemukan pada indeks ke-’,i)
else
output(data_cari,’ tidak ditemukan’)
endif
EndProcedure](https://image.slidesharecdn.com/chapter11-searching-161018112309/85/Algorithm-and-Programming-Searching-16-320.jpg)
![Data that was sought: 7
Number
Result: ?
CaseExampleofBinarySearch
3 7 12 15 29
[1] [2] [3] [4] [5]](https://image.slidesharecdn.com/chapter11-searching-161018112309/85/Algorithm-and-Programming-Searching-19-320.jpg)
![Case Example of Binary Search
Data that was sought: 7
Number
Result: ?
3 7 12 15 29
[1] [2] [3] [4] [5]](https://image.slidesharecdn.com/chapter11-searching-161018112309/85/Algorithm-and-Programming-Searching-20-320.jpg)
![Case Example of Binary Search
Step 1 : Divide array into 2 parts. Count the middle
position (k) of array to start searching
k = (Ia + Ib) div 2
= (1 + 5) div 2
= 3
la : lower bound (for index)
lb : upper bound (for index)
3 7 12 15 29
[1] [2] [3] [4] [5]
Ia k Ib
Left Side Right Side](https://image.slidesharecdn.com/chapter11-searching-161018112309/85/Algorithm-and-Programming-Searching-21-320.jpg)
![Case Example of Binary Search
Step 3 : repeat step 1 until step 2 until data is found or until
la>lb then stop searching.
Result : 7 is found in Number[2] and in the third looping.
3 7
1 2
Ia Ib
k
Left Side Right Side](https://image.slidesharecdn.com/chapter11-searching-161018112309/85/Algorithm-and-Programming-Searching-23-320.jpg)
![Binary Search
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Procedure BinarySearch (Input nama_array : tipe_array)
{I.S. : elemen array yang terurut secara ascending sudah terdefinisi}
{F.S. : menampilkan data yg dicari ditemukan atau tidak ditemukan}
Kamus:
Ia, Ib, k : integer
ketemu : boolean
data_cari : tipedata
Algoritma:
input(data_cari)
Ia 1
Ib maks_array
ketemu false
while (not ketemu) and (Ia ≤ Ib) do
k (Ia + Ib) div 2
if (nama_var_array[k] = data_cari)
then
ketemu true
else
if (nama_var_array[k] < data_cari)
then
Ia k + 1
else
Ib k – 1
endif
endif
endwhile](https://image.slidesharecdn.com/chapter11-searching-161018112309/85/Algorithm-and-Programming-Searching-24-320.jpg)
Algorithm and Programming (Searching)
- 1. Adam Mukharil Bachtiar English Class Informatics Engineering 2011 Algorithms and Programming Searching
- 2. Steps of the Day Let’s Start Definition of Searching Sequential Search Binary Search
- 3. Definition of Searching All About Searching
- 4. WhatisSearching Process that search the value in group of data. This process can produce FOUND or NOT FOUND value.
- 5. AlgorithmsofSorting • Sequential search / Linear search • Binary search
- 6. Sequential Search Definition and Structures of Sequential Search
- 7. WhatisSequentialSearch • Trace group of data one by one. • Start the process from the first data. • If the data was found in group then stop the searching but if not, search until the last data in grup.
- 8. MethodsinSequentialSearch • Without boolean Without sentinel Use sentinel • Use boolean
- 9. Ilustration of Seq. Search Without Sentinel Given an array to be processed: Number Data that want to be sought : 9 • Number[1] = 9? • Number[2] = 9? • Number[3] = 9? Result: 9 is found in number[3] 5 1 9 4 2 [1] [2] [3] [4] [5] i i + 1 i i + 1 i (STOP SEARCH)
- 10. Sequential Search Without Sentinel 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Procedure SeqSearchTanpaSentinel (Input nama_array:tipe_array) {I.S. : elemen array [1..maks_array] sudah terdefinisi} {F.S. : menampilkan hasil pencarian (ditemukan/tidak)} Kamus: i : integer data_cari : tipedata Algoritma: input(data_cari) i 1 while(nama_array [i] ≠ data_cari) and (i < maks_array) do i i + 1 endwhile if (nama_array[i] = data_cari) then output(data_cari,’ ditemukan pada indeks ke-’,i) else output(data_cari,’ tidak ditemukan’) endif EndProcedure
- 11. SequentialSearchUseSentinel • Place the data that want to be sought in sentinel. • Sentinel is additional index that was placed in max array + 1. • If the data is found in sentinel that means the result is data is not found and vice versa.
- 12. Ilustration of Seq. Search Use Sentinel Data that was sought: 9 Number Result: Data was found in Number[3] Data that was sought: 10 Number Result: Data was not found 5 1 9 4 2 9 [1] [2] [3] [4] [5] [6] sentinel 5 1 9 4 2 10 [1] [2] [3] [4] [5] [6] sentinel
- 13. Sequential Search Use Sentinel 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Procedure SeqSearchSentinel (Input nama_array:tipe_array) {I.S. : elemen array [1..maks_array] sudah terdefinisi} {F.S. : menampilkan hasil pencarian (ditemukan/tidak)} Kamus: i : integer data_cari : tipedata Algoritma: input(data_cari) i 1 nama_array(maks_array + 1) data_cari while (nama_array [i] ≠ data_cari) do i i + 1 endwhile if (i < maks_array+1) then output(data_cari,’ ditemukan pada indeks ke-’,i) else output(data_cari,’ tidak ditemukan’) endif EndProcedure
- 14. SequentialSearchUseBoolean • Its searching process is similar with another sequential search method. • Involves one boolean variable.
- 15. Ilustration of Seq. Search Use Boolean Given an array to be processed: Number Data that want to be sought : 9 • Number[1] = 9? • Number[2] = 9? • Number[3] = 9? Result: 9 is found in number[3] 5 1 9 4 2 [1] [2] [3] [4] [5] FOUND FALSE FOUND FALSE FOUND TRUE (STOP SEARCH)
- 16. Sequential Search Use Sentinel 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Procedure SeqSearchBoolean (Input nama_array:tipe_array) {I.S. : elemen array [1..maks_array] sudah terdefinisi} {F.S. : menampilkan data yg dicari ditemukan atau tidak ditemukan} Kamus: i : integer ketemu : boolean data_cari : tipedata Algoritma: input(data_cari) i 1 ketemu false while (not ketemu) and (i ≤ maks_array) do if(nama_var_array(i) = data_cari) then ketemu true else i i + 1 endif endwhile if (ketemu) then output(data_cari,’ ditemukan pada indeks ke-’,i) else output(data_cari,’ tidak ditemukan’) endif EndProcedure
- 17. Binary Search Definition and Structures of Binary Search
- 18. WhatisBinarySearch • Searching algorithm that divide group of data into two parts (left and right). • First, check data in the middle. If same with the data that was sought then data is found. If not then continue searching process to left or right (based on condition). • Group of data must be sorted before the searching process.
- 19. Data that was sought: 7 Number Result: ? CaseExampleofBinarySearch 3 7 12 15 29 [1] [2] [3] [4] [5]
- 20. Case Example of Binary Search Data that was sought: 7 Number Result: ? 3 7 12 15 29 [1] [2] [3] [4] [5]
- 21. Case Example of Binary Search Step 1 : Divide array into 2 parts. Count the middle position (k) of array to start searching k = (Ia + Ib) div 2 = (1 + 5) div 2 = 3 la : lower bound (for index) lb : upper bound (for index) 3 7 12 15 29 [1] [2] [3] [4] [5] Ia k Ib Left Side Right Side
- 22. Case Example of Binary Search Step 2 : • check data in k. If it’s same with data that was sought then stop search and data is found. • If it’s not then check whether data was bigger or smaller than data in k. • If it’s bigger one then continue searching to right side and la = k+1. if it’s smaller one then continue searching to the left side and lb = k-1 (data wa sorted in ascending way). 3 7 1 2 Ia Ib
- 23. Case Example of Binary Search Step 3 : repeat step 1 until step 2 until data is found or until la>lb then stop searching. Result : 7 is found in Number[2] and in the third looping. 3 7 1 2 Ia Ib k Left Side Right Side
- 24. Binary Search 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Procedure BinarySearch (Input nama_array : tipe_array) {I.S. : elemen array yang terurut secara ascending sudah terdefinisi} {F.S. : menampilkan data yg dicari ditemukan atau tidak ditemukan} Kamus: Ia, Ib, k : integer ketemu : boolean data_cari : tipedata Algoritma: input(data_cari) Ia 1 Ib maks_array ketemu false while (not ketemu) and (Ia ≤ Ib) do k (Ia + Ib) div 2 if (nama_var_array[k] = data_cari) then ketemu true else if (nama_var_array[k] < data_cari) then Ia k + 1 else Ib k – 1 endif endif endwhile
- 25. Binary Search 27 28 29 30 31 32 33 if (ketemu) then output(data_cari,’ ditemukan pada indeks ke-’,k) else output(data_cari,’ tidak ditemukan’) endif EndProcedure
- 26. Contact Person: Adam Mukharil Bachtiar Informatics Engineering UNIKOM Jalan Dipati Ukur Nomor. 112-114 Bandung 40132 Email: [email protected] Blog: http://adfbipotter.wordpress.com Copyright © Adam Mukharil Bachtiar 2011