The common approach to get a unique collection of items is to use a set. Sets are unordered collections of distinct objects. To create a set from any iterable, you can simply pass it to the built-in set() function. If you later need a real list again, you can similarly pass the set to the list() function. The following example should cover whatever you … Read more
That heavily depends on the structure of the search tree and the number and location of solutions (aka searched-for items). If you know a solution is not far from the root of the tree, a breadth first search (BFS) might be better. If the tree is very deep and solutions are rare, depth first search … Read more
As others have pointed out, due to not using understandable variable names, it is almost impossible to debug your code. Following the wiki article about Dijkstra’s algorithm, one can implement it along these lines (and in a million other manners): This code is more verbous than necessary and I hope comparing your code with mine … Read more
Here a more mathematical way of seeing it, though not really complicated. IMO much clearer as informal ones: The question is, how many times can you divide N by 2 until you have 1? This is essentially saying, do a binary search (half the elements) until you found it. In a formula this would be … Read more
As others have pointed out, due to not using understandable variable names, it is almost impossible to debug your code. Following the wiki article about Dijkstra’s algorithm, one can implement it along these lines (and in a million other manners): This code is more verbous than necessary and I hope comparing your code with mine … Read more
I cannot understand how to identify a function with a log time. The most common attributes of logarithmic running-time function are that: the choice of the next element on which to perform some action is one of several possibilities, and only one will need to be chosen. or the elements on which the action is … Read more
That’s the “forall” (for all) symbol, as seen in Wikipedia’s table of mathematical symbols or the Unicode forall character (\u2200, ∀).
Consider tracing the values: Prints: The first column is ans, which is the sum of the current subarray. The second is sum, representing the sum of the greatest seen so far. The third is the element that was just visited. You can see that the contiguous subarray with the largest sum is 4, −1, 2, … Read more
In simple words, a loop invariant is some predicate (condition) that holds for every iteration of the loop. For example, let’s look at a simple for loop that looks like this: In this example it is true (for every iteration) that i + j == 9. A weaker invariant that is also true is that i >= 0 && … Read more
In simple words, a loop invariant is some predicate (condition) that holds for every iteration of the loop. For example, let’s look at a simple for loop that looks like this: In this example it is true (for every iteration) that i + j == 9. A weaker invariant that is also true is that i >= 0 && … Read more