Nested loops can be a headache, but here's how I think about them: the outer loop controls rows, the inner loop handles what's in each row. For patterns like these, start by figuring out how many rows you need and what changes between them. Then, focus on one row at a time - what number are you printing, and how many times? The outer loop usually sets up the number, while the inner loop prints it. Don't sweat it if it doesn't click right away. Start with simpler patterns and work your way up. Play around with the loops, changing values to see what happens. It'll start making sense with practice. More on reddit.com

Could you show us some examples of exercises you're having problems with? More on reddit.com

I was successful for a role of the same level about 2 months ago and was asked the following three questions in my interview: Tell me what you know about MVC? How would you approach finding a solution to a problem/bug in your code? Why might an SQL query suddenly begin to perform much slower than usual standards? Fairly simple and straight forward, I only really struggled on the last question as I didn't have any idea about indexing before. The rest of the interview was mostly asking about what kind of projects I had worked on in uni or any other relevant experience I had, followed by a bit about myself as an individual. I was a bit shocked that the questions were as simple as they were, but was later told I had a positive attitude to learning and that no graduate/junior is going to know anything vastly complicated and we all need to start somewhere which was good feedback. I hope this is of some use to you and good luck. More on reddit.com

Choose whichever approach is more readable and trust the compiler to optimize. This is the exact kind of thing that Donald Knuth was talking about when he said "premature optimization is the root of all evil". I would suggest you write it closer to the second way with the declaration on the same line. This expresses your intent (your int that the variable is to be used inside the loop) and prevents the outside scope from being polluted with that variable. If you loop contents are simple enough you can do away with the variable entirely by placing your expression directly inside the parameter list for push back: MyVector.push_back(someFunction()); In practice compilers can optimize little things like this way and you should just focus on picking a decent algorithm and implementing it. Then if the product is too slow, which it almost never is in C++, then you can pull out a profiler and actually measure what part of your program is too slow. More on reddit.com