codingbat | Solutions to CodingBat problems | Learning library

I am practicing on CodingBat and trying the below question:

We want to make a row of bricks that is goal inches long. We have a number of small bricks (1 inch each) and big bricks (5 inches each). Return True if it is possible to make the goal by choosing from the given bricks.

Test cases:

• make_bricks(3, 1, 8) → True
• make_bricks(3, 1, 9) → False
• make_bricks(3, 2, 10) → True
• make_bricks(7, 1, 13) → False
• make_bricks(1, 4, 12) → False

When I run on my code on code editor(VSCode), I pass every test cases but when I do submit on the CodingBat(https://codingbat.com/prob/p118406) I am getting and error as Time out. Please can anyone explain me why or is there any error in my code below:

This is my first time posting to Stackoverflow.

I'm trying to solve this problem here: https://codingbat.com/prob/p270692?parent=/home/konstans@stuy.edu/all

When looking at all hailstone sequences from 1 to z, maxHail(z) will return the starting number that creates the longest sequence. In other words, maxHail(n) looks at hailLen(1), hailLen(2) ... hailLen(n) and returns the number from 1-n that had the largest hailstone sequence. You should look at the hailLen() problem before working on this. You should use your solution from the hailLen() problem. ( http://codingbat.com/author/p264289 ) since hailLen(3) is larger than the hailLen of 4 or 5, maxHail of 3,4,5 all return 3. Since 6 has a longer sequence, maxHail(6) gives us 6. remember: Use the hailLen function you already wrote!

Here's my code and the output:

However, I'm not sure where this goes wrong - I checked line-by-line and couldn't see anything wrong. Could anyone help me fix this? Thank you!

I am currently doing a problem on coding bat called string_bits and have been debugging it using Thonny and putting the code into coding bat to see if it is correct. Right now I am getting an error with my code in codingbat that says string index out of range. The weird thing is when I run it in Thonny I don't get the error. What is happening here?

I am currently doing an exercise on CodingBat that goes as follows:

Given 2 int values, return True if one is negative and one is positive. Except if the parameter "negative" is True, then return True only if both are negative.

This is my initial attempt:

i wanted to ask what helped you grasp the concept of backtracking better.

I think i understand the idea behind it and recursion well enough, yet, i struggle to make sense of why backtracking leads to the wanted outcome. I tried to "dry run" the code on paper, and understand the program flow better, but to almost no avail.

So, naturally, i have a extremely hard time to come up with my own backtracking solutions.

I think i understand why the base case makes sense, why the if-calls are necessary, and see that every option is being checked (by using a debugger), yet i do not see why java computes the code that way internally.

For example here: https://codingbat.com/prob/p145416:

Codingbat has a practice question Under Logic-1, Python. It's called near_10.

Given a non-negative number "num", return True if num is within 2 of a multiple of 10. Note: (a % b) is the remainder of dividing a by b, so (7 % 5) is 2

The solution on one user's GitHub is given as

I'm practicing code on codingbat and came across this logic question:

Given a number n, return True if n is in the range 1..10, inclusive. Unless outside_mode is True, in which case return True if the number is less or equal to 1, or greater or equal to 10.

The solution is:

The challenge is from codingbat - Sum the elements of the array except for all values between 6 and 7, not counting the 6 or the 7 either.

My strategy was create a new array "valid" and append valid elements of the array nums to the "valid" array, and then sum the valid array.

Because I need the index to check for a 7 once a 6 is detected, my plan was to enumerate the array, and when the value 6 is found, to loop through the remainder of the array until a 7 is found, not appending the values 6-7 to the array "valid" in the process.

I ran my code through the MIT Python tutor to see where it was going wrong, and when I increment the index after i+1 != 7 (with the intention of checking to see if the next value in the array is a 7) it increments the index (it finishes working with that index of the array and moves on to the next one, rather than sticking in the code for the 6 and continuing to loop through and check for a 7).

Appreciate any help with this, especially a solution that sticks to the original strategy but implements it correctly in the code.

The problem statement is as follows:

Return the sum of the numbers in the array, except ignore sections of numbers starting with a 6 and extending to the next 7 (every 6 will be followed by at least one 7). Return 0 for no numbers.

sum67([1, 2, 2]) → 5
sum67([1, 2, 2, 6, 99, 99, 7]) → 5
sum67([1, 1, 6, 7, 2]) → 4

I'm aware of the same problem being posted here on stack overflow but I don't want to request a new solution, rather I want to know what might be the problems with my own recursive solution to the problem.

My attempt: