Below you’ll find a simple C program that creates 5 worker threads. The threads then wait until the main thread gives them a signal to start the work. I employ different primitives to make this synchronization happen. Note: Remember that you need to compile this programs with the -pthread GCC option. Note 2: When you […]
Below you’ll find a list of some basic yet useful Linux commands for the command line interface (i.e., the shell), which is the interface provided by users to interact with services and programs provided by the operating system kernel. 1. man pages When in doubt about a specific command or program, check is manual pages. […]
Find the greatest product of five consecutive digits in the 1000-digit number.
If you never use GDB (The GNU Project Debugger), well, you should! It’s easy to underestimate its usefulness when debugging programs. Below you’ll find some very basic commands that will get you started: First of all you need to compile/assemble your program with the -g flag, which will include in the executable the necessary code […]
This project was done for the ‘Computer Organization and Assembly Language’ class, with Prof. Borin from Unicamp. Below you’ll find the code that runs a very simple operating system in ARM Assembly. On system start the OS will configure some pieces of hardware (e.g., GPT, UART and TZIC) and it will setup the environment (supervisor […]
The problem: — A permutation is an ordered arrangement of objects. For example, 3124 is one possible permutation of the digits 1, 2, 3 and 4. If all of the permutations are listed numerically or alphabetically, we call it lexicographic order. The lexicographic permutations of 0, 1 and 2 are: 012 021 102 120 201 […]
The problem: — A perfect number is a number for which the sum of its proper divisors is exactly equal to the number. For example, the sum of the proper divisors of 28 would be 1 + 2 + 4 + 7 + 14 = 28, which means that 28 is a perfect number. A […]
The problem: — By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13. What is the 10 001st prime number? — My solution: .text .globl main main: /*-enter stack frame-*/ pushl %ebp movl %esp, %ebp movl $3, %edi movl $1, %esi mainLoop: […]
The problem: — Using names.txt (right click and ‘Save Link/Target As…’), a 46K text file containing over five-thousand first names, begin by sorting it into alphabetical order. Then working out the alphabetical value for each name, multiply this value by its alphabetical position in the list to obtain a name score. For example, when the […]
The problem: —— The sum of the squares of the first ten natural numbers is, 12 + 22 + … + 102 = 385 The square of the sum of the first ten natural numbers is, (1 + 2 + … + 10)2 = 552 = 3025 Hence the difference between the sum of the […]