String operation
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The document discusses string operations and storage in programming languages. It describes the basic character sets used which include alphabets, digits, and special characters. It then discusses three methods of storing strings: fixed-length storage, variable-length storage with a fixed maximum, and linked storage. The document proceeds to define common string operations like length, substring, indexing, concatenation, insertion, deletion, replacement, and pattern matching. Algorithms for implementing some of these operations are provided.
String operation
- 2. 2 Data Structures and Algorithms Remarks • Each programming language contains a character set that is used to communicate with the computer. This set usually includes the followings- • Alphabet- A B C D… X Y Z • Digits- 0 1 2.. 9 • Special Characters- + - / * . (), {}, , $ etc.. ©SMT, Faculty, CSE, IUBAT
- 3. 3 Data Structures and Algorithms Storing String • For Example, ©SMT, Faculty, CSE, IUBAT
- 4. 4 Data Structures and Algorithms Storing String • 1. Fixed- length storage. ©SMT, Faculty, CSE, IUBAT
- 5. 5 Data Structures and Algorithms Storing String • 1. Fixed- length storage. ©SMT, Faculty, CSE, IUBAT
- 6. 6 Data Structures and Algorithms Storing String • 2. Variable- length storage with fixed maximum. ©SMT, Faculty, CSE, IUBAT
- 7. 7 Data Structures and Algorithms Storing String • 2. Variable- length storage with fixed maximum. ©SMT, Faculty, CSE, IUBAT
- 8. 8 Data Structures and Algorithms Storing String • 3. Linked storage ©SMT, Faculty, CSE, IUBAT
- 9. 9 Data Structures and Algorithms String Operation • Length: LENGTH (string) e.g.- LENGTH(‘Mark Zuckerberg’)= 15 • Substring: SUBSTRING(string, initial, length) e.g.- SUBSTRING(‘Impossible is a word found in coward’s dictionary’,0,20) = Impossible is a word • Indexing: INDEX(string, pattern) e.g.- INDEX(‘He is wearing glasses’, ‘ear’)= 8 • Concatenation: String1//String2 e.g.- ‘To be or not to be’// ‘, this is the question.’= To be or not to be, this is the question ©SMT, Faculty, CSE, IUBAT
- 10. ©SMT, Faculty, CSE, IUBAT String Operation • Word Processing- Insertion: INSERT(string, position, string) e.g.- INSERT(‘ABCDEIJKL’,5,‘FGH’)= ABCDEFGHIJKL Deletion: DELETE(string, position, length) e.g.- DELETE(‘ABCDEFG’, 4, 2)= ABCDG
- 11. 11 Data Structures and Algorithms String Operation – Replacement: REPLACE(string, pattern1, pattern2) e.g.- REPLACE(‘XABYABZ’, ‘AB’, ‘c’)= XCYABZ REPLACE function can be executed be using the following three steps- 1. K:= INDEX(string, P1) 2. T:= DELETE(string, K, LENGTH(P1)) 3. INSERT(T, K, P1) – So, the algorithm is- ©SMT, Faculty, CSE, IUBAT
- 12. 12 Data Structures and Algorithms String Operation – Pattern Matching: Pattern matching is the problem of deciding whether or not a given string pattern P appears in a text. Widely used in word processing. – So, a basic algorithm is- ©SMT, Faculty, CSE, IUBAT