I'll show you sort(v.begin(), v.end()) to arrange elements in ascending order. The function takes two iterators marking the start and end of the range to sort. You can sort part of a vector: sort(v.begin(), v.begin() + 5) sorts only the first five elements.
Elements beyond position 5 remain in their original order. Time complexity is , making it efficient even for large arrays. You'll use this algorithm more frequently than any other in competitive programming.