I posted an improved version of this answer on a duplicate of this: C loop optimization help for final assignment. It was originally just a repost, but then I made some changes to answer the differences in that question. I forget what’s different, but you should probably read that one instead. Maybe I should just … Read more
The best optimization, for size, speed, cleverness, clarity, and anything else you may think of, is to have no code. So, just remove those 4 lines from your source(s) and you’ve optimized your code.
std::forward_list::max_size returns the maximum number of elements that the forward_list container can hold. Your forward list implementation should be: //Forward list template<> struct F22<true>{ template<typename T> static void F23(const string& name, const T& a){ std::size_t i = 0; for (const auto& e : a) { std::cout << name << “[” << i << “]: ” … Read more
Lazy evaluation will not make bad algorithms perform better. It will just delay when those performance problems will affect you. What lazy evaluation can help with is space complexity, i.e. reducing the amount of memory you need to execute your algorithm. Since the data is generated lazily, you will not (necessarily) have all the data … Read more
BigInteger has the divideAndRemainder(…) method, one that returns a BigInteger array, the first item the division result, and the second, the remainder (which is what mod really does in Java). Update Including comment by Mark Dickinson to other answer: There’s a much simpler linear-time algorithm: set acc to 0, then for each digit d in … Read more
Calculate the cumulative sum of the array and store it in another one, that is to say, accumulated[i] = sum of numbers of the array up to ith index. This can be computed in O(n). Then for a query, the answer will be accumulated[r] – accumulated[l]. This is O(1)
This seems like it was purposefully un-optimized. I would assume that the time constraints are coming from modding a variable 100,000,000,000 times. But wait, that is not all. Not only do you mod a variable that many times, but when a variable modded to 0, you iterate another 11 times over each char in “Hello … Read more