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1answer
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cs50w project1 - AttributeError: 'NoneType' object has no attribute '_instantiate_plugins'

I am trying to import the books.csv file into the online PostgreSQL database via Python code, as shown in the lectures and I get this error message when sqlalchemy is attempting to create the engine. ...
3
votes
1answer
928 views

What does seeding mean in rand function?

what does seeding mean? in pset3 generate.c they have called srand() if seed number is given or srand((unsigned int) time(NULL)); what does time(null) do? after this for each random number to be ...
3
votes
1answer
251 views

Where to host a website [closed]

Can someone make a recommendation at to what provider to use to host a website for the final project? This would be for an Edx student so not eligible for Harvard's web hosting
2
votes
1answer
149 views

Adding CS50.h to MacOS?

I've been trying to import the cs50.h library by all ways to my mac or xcode with no luck, I followed the instructions on https://manual.cs50.net/library/ nothing is working Do you have any ...
2
votes
2answers
554 views

Algorithm to count 729 students in the classroom

I don't understand the logic behind the algorithm of counting all the 729 students in the auditorium. It seems to be working (though the result 637 is not exactly the same.). But I don't know how it ...
2
votes
1answer
34 views

Are the CS50 Live videos important for completing the course?

On the CS50 Course Info page (on edX) there is a playlist of videos. Thinking that it might be important I watched them. Up to the 7th on the playlist, I question whether I am only wasting my time ...
2
votes
1answer
100 views

Is it possible to teach cs50?

I was wondering if it is possible to teach cs50 in my hometown once I have finished the course (which I am about to finish). Are there any restrictions? Do I have to ask permission, if that is the ...
2
votes
2answers
59 views

VMware player 6 problem installation

My computer does not have a HAV capable processor, that is why it does not have hardware-assisted virtualization. I cannot install your enviroment (VMware player 6) that you recommended. What should ...
1
vote
1answer
106 views

Can I use my Scratch project at work?

I was reading the section about academic honesty and got to the part where it said that it was unacceptable to submit work to this course that you intend to use outside of the course (e.g., for a job) ...
1
vote
2answers
790 views

local subtitles

I just started CS50. I can't find the option to turn off the subtitles. Anyone has an idea? I get these annoying subtitles in the bottom of the video, in white. They are in portuguese (which is my ...
1
vote
3answers
78 views

avoiding typing due to injury

Are there any adaptive technologies for typing in the terminal window? I love the cs50x class, but I have a history of repetitive strain injury. I can use typing-by-voice for word processing ...
1
vote
2answers
424 views

Why does traceroute's path not make sense and what exactly is nslookup?

traceroute: When trying to trace route for facebook.com (I am from India), I get below response. Now, as per the lecture, first few IP addresses or router names are the nearest routers to me. But 1st ...
1
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3answers
119 views

What does 'random access' mean?

I've seen several different definitions by googling, but I am still not sure. David kept saying "array gives us random access, and trie, too". What does 'random access' mean?
1
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1answer
172 views

problem with my cash file in pset1

its still showing me the same error.. make: *** No rule to make target `cash'. Stop.
1
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2answers
61 views

what is the maximum input value for greedy?

The maximum input value that the "official" reply will calculate is 21474834 which gives an answer of 85899339; which is correct. However if 21474835, or anything higher, is input, the answer is 0. ...
1
vote
1answer
29 views

Using Stack Exchange

How to type the code (code would come seperately)? Can anybody help me? I am using it about two three weeks, but can not understand ( I also tried to read the instruction but wasn't helpful)
1
vote
0answers
115 views

picatic the puzzle day

Can anybody tell me what the first puzzle is about? What the images show? Link for the question is https://medium.com/@cs50/this-was-cs50x-puzzle-day-2016-1b1519b77353 2017 question
1
vote
1answer
45 views

Week6, week11 and quizzes

I have forgotten why there is not a week 6/11 in the Courseware and do i have to go somewhere to make quizzes? Excuse me if i´m kind of lost here.
0
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2answers
66 views

an AI which learns [closed]

i was wondering how can an AI learn? for example:after observing 1000 people hacking,it learns to hack or in a video game,by watching that his method is not effective, based on what the opponent is ...
0
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2answers
701 views

expected identifier or '(' { error

I'm trying to run this code and here's the error that i get: clang -fsanitize=signed-integer-overflow -fsanitize=undefined -ggdb3 -O0 -std=c11 -Wall -Werror -Wextra -Wno-sign-compare -Wshadow zeki....
0
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2answers
45 views

pset5-speller: dependency issue

Please, I need your help. I have dependency issue with my code. This is check50 response on my code. I guess the problem is with my load function. After a few tweaks on the code to fix the dependency ...
0
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1answer
25 views

Hey guys i am new in cs50 and i am struggling to submit my CaeserCipher assignments please help

please assist I really need to submit my work.
0
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1answer
339 views

CS50x Problem set week 0 Objective?

I am from colombia. Sorry If my english is not perfect !! I subscribed to CS50x and just completed the lecture. Now I am ready for problem set 0. The description for problem set is only "program in ...
0
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2answers
300 views

is my implementation to insertion sort correct?

is my implementation to insertion sort correct? for(int i = 0; i < n; i++) { for(int j = i; j > 0; j--) { int t; if(a[j] < a[j - 1]) { t = a[j - 1]...
0
votes
1answer
152 views

hacker1 - "error: expected expression" using nested ternary operator

For the hacker edition of pset1 I'm working on credit.c. So far, I'm progressing nicely. However, I decided using a Ternary Operator assigning a value to the string variable ccType using the code ...
0
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2answers
207 views

I have done some coding before. How much time will I take to complete CS50

I have a quick question. I have some programming experience C and C++ ... Can you please tell me how much time( roughly ) will I take to complete CS50 ? Also is honor code certificate signed by ...
0
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2answers
23 views

What is the need of the forever loop while petting a cat?

It doesn't work if we use only if-condition. Why so?
0
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2answers
626 views

algorithm for brute force pset2 hacker edition

I am doing PSET2 "Hacker Edition". I did used dictonary and It worked fine for cracking some passwords.I want to generate all the possible characters in incrementing order but I am unable to think the ...
0
votes
1answer
35 views

Get rid of extension from webpages

When i want to run a php file in the terminal, i do : $php hello.php Now, if i want to get rid of the .php at the end, i can add this at the top of file-> #!/bin/env php Now, in the command line i can ...
0
votes
1answer
10 views

Pset 2 : Readability

In my code, in order to find the number of words by counting the number of spaces, I am having a logical error My intention is to count the number of spaces using a for loop and an 'if' condition. I ...
0
votes
1answer
139 views

Error when fetching data from Heroku Postgresql: AttributeError: 'NoneType' object has no attribute '_instantiate_plugins'

I am getting the following error while fetching data from Heroku, Traceback (most recent call last): File "list.py", line 6, in <module> engine = create_engine(os.getenv("DATABASE_URL")) ...
0
votes
1answer
58 views

PSET5: Serve Greyed Out/ CSS Changes Not Reflected on Page Despite Saves

I'm on to working on my extra HTML and CSS pages for PSET5. I've run HTTP-SERVER, clicked on Port 8080 and selected Open where upon I get a directory tree and select the HTML file I want to run. ...
0
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1answer
338 views

I really want to use Express and Node JS for my final project - is this possible?

I got the app running fine in the terminal but can't seem to get it going in the browser. This is where it should run: https://-.c9users.io I tried inserting my username and the workspace name which ...
0
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2answers
84 views

calling square function

#include <stdio.h> #include <cs50.h> int square (int x); int main(void) { int x = get_int ("x:"); printf("%i\n", square(x)); } int square (int x) //here in this line which ...
0
votes
1answer
10 views

Course was archived but granted access. What affect will this have

Let me start by saying that I have been trying for 2 days to find this answer for myself. I started the CS50 course in 2017 and due to medical reasons could not return to the course until last week. ...
0
votes
1answer
25 views

I have completed all the projects two months ago but no certificate recieved!

I have completed CS50 from 11 September 2017. I still have not received my certificate or any response at all (e.g. my final project did not pass). What should I do? Is there anyone with the same ...
0
votes
1answer
97 views

Why is uncompressed bitmap image checked with the condition biCompression != 0?

For week 4 problem set, in line 50 of copy.c there is a conditional statement to check if the image is uncompressed - biCompression != 0. According to the MSDN documentation for bitMapInfoHeader, the ...
0
votes
1answer
63 views

How to store a Reference board of the original values in sudoku.c

i am looking for help on sudoku.c. i need to store the original numbers that come with the board so that the number values can not be changed. i am having trouble figuring out how to store these ...
0
votes
1answer
190 views

Check_flag in sort race

I have a quick question about the check_flag function in sort race. Just looking for a hint or advice to lead me in the right direction. I cant quite figure out how to reference the argv[1] values. I ...
0
votes
1answer
19 views

Lecture 4 : pointer size question

should the size of int*, double* be the same? (4 or 8?) as the int* just means the data type the pointer points while we are saving the address of a. int a; double b; int is 4 bytes while double is ...
0
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2answers
198 views

Could not load dictionary in cs50 pset5

I wrote the load code for pset5 which compiles but when I execute speller.c it says "Could not load dictionary". I have used both my own dictionary text file and the dictionary at home/cs50/pset5/...
0
votes
1answer
36 views

myspace in study.cs50: How do I walk through the loop correctly?

I've been trying to solve the problems in study.cs50. I know for myspace I need to loop through the input string and stop at spaces, before finally stopping at strlen(input string), (and I'm not doing ...
0
votes
1answer
67 views

line numbers are missing in PDF printout

Can anyone give me clue(s) to solve a PDF printing of my coding? PDF print out of my code is in black only, and does not show color words as in gedit. I have lived with this problem so far. Then only ...
0
votes
1answer
47 views

anyone running the appliance on a new, low cost windows laptop?

I am taking Cs50 in college and I am tired and somewhat worried of lugging around a $2,000 8lb gaming laptop with a huge power brick (my only computer). It seems like a $200 11 inch laptop would be ...
0
votes
1answer
424 views

Does analyzing solutions count as cheating?

When given a problem set, I always try working it out first, then I go on Google and look up multiple solutions. However, I don't copy it. I just break down the code to see the codes and ideas behind ...
0
votes
1answer
337 views

In scratch, How do i make a sound file play when a sprite bounces off the wall?

the command "if touching edge, play sound" doesnt seem to work for bouncing. my goal is to have it play the sound "boing" when it bounces off the wall. thanks for the help!
0
votes
1answer
30 views

don't understand this code

Hi I was reading through howstuffworks for c. Can somebody explain how this is a factorial code int fact(int i) { int j,k; j=1; for (k=2; k<=i; k++) j=j*k; return j; } so ...
0
votes
1answer
51 views

error when type cd CS50 on the terminal

When i open the directory and try comands, like is in the week 1 sections, like cd CS50, I then receive this message: bash: cd: CS50: No such file or directory
0
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2answers
43 views

terminal doesn't respond to more instructions

When I create or search for a file of gedit from the terminal, this execute it but doesn't respond to more instructions after. This is my trouble.I typed in the terminal update50, but the problem ...
0
votes
2answers
54 views

What is required?

I am finished watching the lectures, everything is alright there. When it is time to do the problem sets I am completely lost. I do NOT understand the layout of the problem sets. I am used to having ...