-
Recent Posts
Recent Comments
Archives
Categories
Meta
Category Archives: programming
Logic gates
Here are some basic logic gates and how we can combine them to get an XOR: In order to perform addition of arbitrary length binary numbers we first start with creating a Half Adder, which can add two single binary … Continue reading
C++ Lambda Expressions
Here are some whiteboard notes I created on c++ lambda expressions. I should create a digital/html version of this reference.
Leetcode 50: Pow(x, n)
This problem solution relies on binary exponentiation. The key insight is that 2^10 = 2^5 * 2^52^5 = 2^2 * 2^2 * 2So we can base our solution on recursively solving pow(x, n/2) and multiplying it by itself to get … Continue reading
SudokuSolverX Android app
I’ve created a Sudoku puzzle solving app. See details here:
Leetcode 49: Group Anagrams
Use a hash map with key being the sorted word and value being a vector of strings of all instances of that anagram. Iterate through input array, filling the hash map. Then iterate through the hash map adding the map … Continue reading
Leetcode 48: Rotate Image
The idea with my solution is that you work your way through layers of the box, starting with the outside layer and then moving inwards. For each layer we step through four points at a time, starting at the corners … Continue reading
Leetcode 46: Permutations
The obvious way to solve this is to repeatedly call next_permutation() from the standard library. Another way to solve it is to implement what next_permutation() does and I have done that in a previous solution:https://www.adamk.org/leetcode-31-next-permutation/ Here is my recursive solution … Continue reading
Origins of the C++ name
In Stroustrup’s “A Tour of C++”, it says that C++ takes its name from: The increment operator (++) combined with C programming language name. George Orwell’s novel “1984”. The first was obvious and expected but the second was surprising, so … Continue reading
Leetcode 44: Wildcard Matching
The obvious solution is to use a recursive function. If we find a wildcard then we recurse every position in s from that point onwards. The problem with this is that it is very slow if there are a lot … Continue reading
Leetcode 43: Multiply Strings
The general steps to do long multiplication are fairly straightforward but the implementation was a bit fiddly. I think it would be easier to to reverse the strings and work on them in reverse, then the least significant index will … Continue reading