Blockchain developer
While working with Rust, I find myself implementing a lot of From/Into or TryFrom/TryInto traits in my code. Whether you're dealing with simple conversions or handling more complex scenarios with potential errors, mastering these traits is key to wri...
Introduction If you are confused about what value should be passed into the low and high of Uint256 in Cairo? you are not alone. I was confused the first time I saw it too. After digging into the code and asking around, I finally figured it out. What...
Problem Write a program poly.cairo that computes the expression: $$ x^3 + 23x^2+ 45x + 67 = 0, x = 100 $$ After the program ends, the value should be at [ap - 1]. For this exercise, you may assume that the fp register is constant and initialized to...
Introduction Cairo provides a built-in hash2 function to calculate the Pedersen hash of two felts. In this challenge, we will recursively compute the hash of an array of felts. The challenge ex_hash_chain.cairo // Task: // Develop a function that is...
Introduction In Encode's Cairo Bootcamp, there is an interesting bit manipulation challenge. It took me some time to figure it out. In this article, I will discuss the challenge and the solution. The challenge ex7.cairo %lang starknet from starkware....
Setting up We use protostar to set up a simple Cairo project where we can implement and test our function. protostar init sum-even Algorithm Cairo does not have a standard for loop built-in. To sum even numbers in an array, we use recursion. main.c...
Introduction On June 17, 2016, a hacker drained 3.6 million ETH from TheDao's smart contract. It was the notorious reentrancy attack that led to a hard fork of Ethereum which became Ethereum Classic (ETC). After the attack, developers were educated t...
TL;DR If you are familiar with Merkle tree and want to jump to the code. Here you go: Simplified codes that I use in this article: Github A more DRY version that you can reuse in your project: Github Introduction NFT whitelisting is a way to reward...