Final Exam Discussion Janani Kalyanam

gradebook.c ● Each field may need an single or multidimensional array. (may need additional arrays as well).

● Alternatively, could store the current version of the database in a file. Can re-write the file whenever necessary.

gradebook.c ● Adding a record: ○ must change all the fields simultaneously if using arrays to store database ○ must read from, and write to the same file if using file to store database

● Deleting a record: ○ must delete all the fields simultaneously, and fill in the cleared space by "scootching" if using arrays (must be careful with indexing) ○ must read from, and write to the same file if using file to store database

gradebook.c ● Keyword search: ○ string.h has strcmp function that compares 2 strings. Example: strcmp("apples","oranges") returns -1; strcmp("oranges","apples") returns +1 strcmp("apples","apples") returns 0 stricmp() and strcasecmp() for case-insensitive comparisons. stricmp("apples",AppLES") will return 0

gradebook.c ● keyword search (contd.): ○ Must read user input as string. ○ atoi() in the standard library will be useful. ■ converts string to integer. ●

Reporting statistics: ○ Use formula to calculate final number. ○ Histograms (use arrays)

●

Some constants ○ 511 ○ 16

similarity ● similarity between two files ● word-frequency table "Tarantino spent a decade writing the script for this film. Tarantino viewed the script as his masterpiece in the making, so he wanted it to be his best ever. According to Tarantino, all his films make the audience laugh at things that are not funny."

similarity ● Need multi dimensional arrays to store words

● word is defined as a sequence of chars separated by a space or newline

similarity sqrt(4*4 + 2*2 + 3*3 + 2*2 + 1*1 + 1*1) * ... 2010

4

2010

6

my

2

my

2

his

3

his

4

the

2

the

1

Brad

1

Angelina

1

Pitt

1

Jolie

1

similarity ● (4*6) + (2*2) + (3*4) + (2*1) = numerator common words

# occurrances in file1

# occurrances in file 2

2010

4

6

the

2

2

my

3

4

his

2

1