HarvardX CS50 2018

CS50 Library for C

Here's the list of the tasks I've made for the course.

WEEK 0: Scratch

Link to my project in Scratch

WEEK 1: C

Hello

Task: Implement a program that prints out a simple greeting to the user, per the below.

$ ./hello
hello, world

hello.c

Mario

Task: Implement a program that prints out a half-pyramid of a specified height, per the below.

$ ./mario
Height: 5
    ##
   ###
  ####
 #####
######

mario1.c

Mario2

Task: Implement a program that prints out a double half-pyramid of a specified height, per the below.

$ ./mario
Height: 4
   #  #
  ##  ##
 ###  ###
####  ####

mario2.c

Cash

Task: Implement a program that calculates the minimum number of coins required to give a user change.

$ ./cash
Change owed: 0.41
4

cash.c

Credit

Task: Implement a program that determines whether a provided credit card number is valid according to Luhn’s algorithm.

$ ./credit
Number: 378282246310005
AMEX

credit.c

WEEK 1 (continued): Crypto

Caesar

Task: Implement a program that encrypts messages using Caesar’s cipher, per the below.

$ ./caesar 13
plaintext:  HELLO
ciphertext: URYYB

caesar.c

Vigenère

Task: Implement a program that encrypts messages using Vigenère cipher, per the below.

$ ./vigenere ABC
plaintext:  HELLO
ciphertext: HFNLP

vigenere.c

Crack

Task: Implement a program that cracks passwords, per the below.

$ ./crack 50fkUxYHbnXGw
rofl

crack.c

WEEK 2: Music

Music

Task:

• Learn to read sheet music.
• Learn to read code.
• Convert musical notes to frequencies.
• Synthesize songs.

Music

WEEK 3: Forensics

Whodunit

Task: Answer some questions and then implement a program that reveals a hidden message in a BMP, per the below.

$ ./whodunit clue.bmp verdict.bmp

Whodunit

Resize (Less)

Task: Implement a program that resizes BMPs, per the below.

$ ./resize 4 small.bmp large.bmp

Resize(Less)

Resize (More)

Task: Implement a program that resizes BMPs, per the below.

$ ./resize .25 large.bmp small.bmp
$ ./resize 4 small.bmp large.bmp

Resize(More)

Recover

Task: Implement a program that recovers JPEGs from a forensic image, per the below.

$ ./recover
Usage: ./recover image
$ echo $?
1

$ ./recover card.raw
$ echo $?
0

Recover

WEEK 4: Mispellings

Speller

Task: Implement a program that spell-checks a file, per the below.

$ ./speller texts/lalaland.txt
MISSPELLED WORDS

[...]
AHHHHHHHHHHHHHHHHHHHHHHHHHHHT
[...]
Shangri
[...]
fianc
[...]
Sebastian's
[...]

WORDS MISSPELLED:
WORDS IN DICTIONARY:
WORDS IN TEXT:
TIME IN load:
TIME IN check:
TIME IN size:
TIME IN unload:
TIME IN TOTAL:

Speller

WEEK 7: Déjà vu

Sentimental

Task: Implement the below exactly as specified but in Python

• hello.py
• mario1.py
• mario2.py
• cash.py
• cash_function.py
• credit.py
• caesar.py
• vigenere.py
• crack.py

Similarities (Less)

Task:

1. Implement a program that compares two files for similarities.
2. Implement a website that highlights similarities across files, a la the below.

Similarities(Less)

Similarities (More)

Task:

1. Implement a program that measures the edit distance between two strings.
2. Implement a web app that depicts the costs of transforming one string into another.

Similarities(More)

WEEK 8: C$50 Finance

C$50 Finance

Task: Implement a website via which users can "buy" and "sell" stocks.

C$50 Finance

WEEK 9: Mashup

Mashup

Task: Implement a website that lets users search for articles atop a map.

Mashup