It will be much easier to understand what is happening if you start with what happens closer to the base case of the recursion. Suppose you have fun(0) in your main. inside the body of fun this happens: void fun(int n) { if(n > 0) //this is false, so function does nothing { fun(n-1); printf(“%d … Read more
First, you are accessing an uninitialized variable. This introduces undefined behaviour into your program; I’d remove this section. Second, your while-loop runs as long as a > 0, but in the body of the loop, the value of a is never changed. Note that when calling init, parameter a is passed by value, i.e. the … Read more
Recursion: simplify the problem, solve the simpler one Example: the multiplication of all the numbers from N to 1 1 * 2 * 3 * 4 * 5 * 6 * … * N Simplification: the multiplication of all the numbers from N to 1 is N multiplied by the multiplication of all the numbers … Read more
This sequence is Stern’s diatomic sequence, and the function you’ve been given is called fusc(n). One way to compute it in O(log n) time and O(1) space complexity is to find the n’th value in the Calkin-Wilf tree. That value’s numerator will be fusc(n). You can read some background on the wikipedia page: https://en.wikipedia.org/wiki/Calkin%E2%80%93Wilf_tree Here’s … Read more
I can correct this by adding the else clause, but how come if there is no outcome handled by default, the function tries to return a Unit? In Scala, unlike more “imperative” languages, (almost) everything is an expression (there are very few statements), and every expression evaluates to a value (which also means that every … Read more
Recursion works by breaking down each problem to a “smaller” version of the same problem. In this case, you can insert this code: elif n < 0: return False elif is_buyable(n – 20) or is_buyable(n – 9) or is_buyable(n – 6): return True 4 solved Python Recursion Puzzle: Buying n McNuggets at McDonalds (using 6, … Read more
There’s no difference. C doesn’t specify the order of execution of the * operands, so a * b and b * a are effectively equivalent, for any expressions a and b. solved What is the Difference between two code snippets? [closed]
I understand the down-votes and the closing votes, since you don’t show the slightest effort here. On the other hand, this is a non-trivial problem. I will assume for a second that you are genuinely interested in a solution to this problem and I’ll show you how I would write this (without having looked too … Read more
can you try the following piece of code. #include<stdio.h> count(int); int main() { int x=4; count(x); return 0; } int count(int n) { if(n>0) { printf(“%d”,n); return count(n-1); } else { printf(“%d”,n); return n; } } 4 solved How recursion works in this code? [duplicate]
and totally redeem yourself ! SO likes to punish people if they don’t show their work, but I’m not one to judge. I do think you will learn more if you try these problems on your own, but I know what it’s like to be completely bewildered; and no good-natured soul amongst us wants to … Read more
The C++ code doesn’t work perfectly. It’s undefined behavior and everything can happen. That includes working, just suddenly stopping to work tomorrow, or on Christmas eve and delete all your files… C++ standard draft n4527 (6.6.3/2 [stmt.return]): The expression or braced-init-list of a return statement is called its operand. A return statement with no operand … Read more
While @SamGrondahl is on the right track, unfortunately, if you enter a negative number it gives unexpected results. This should work properly with negative numbers: int sumdigits(int number) { int sign = number < 0 ? -1 : 1; number = sign * number; // abs the number if (number < 10) return sign * … Read more
I just coded a node js code, you can still make it work on a browser in js, but you will need to download the underscore library here. _und = require(‘underscore’); data = [{ “id”: 1, “children”: [{ “id”: 7, “children”: [{ “id”: 8, “children”: [{ “id”: 4 }, { “id”: 5 }, { “id”: … Read more
Recursion doesn’t seem to be necessary for the “parent” direct values, so that can be done with a direct foreach loop. The “children” indirect values require recursion. I’ve elected to use array_walk_recursive() to access every “leaf node” in the array. This will also store the parents’ indirect values too, so I subtract those values after … Read more
Use lengths of the lists to terminate the recursion. In this example implementation, if length of either of the lists is 0, we have either mapped it all, or it is an empty list to begin with, thus we terminate the recursion. Also worth noting that l1[1:] is the slice of the list we haven’t … Read more