Users' questions

Are sets indexed C++?

Are sets indexed C++?

set doesn’t have access by index. You can get the nth element like this: std::set::iterator it = my_set.

How do I get the index of a set element in C++?

Approach: Follow the steps below to solve the problem:

  1. Initialize a variable, say index as 1, to store the index of the required element.
  2. Traverse the set S and perform the following operations:
  3. If the current element is K, print Index and break out of the loop.
  4. Otherwise, increment Index.

How do you find the index of an element in a set?

Method 1: Using Array

  1. Import the required Java package java.util.
  2. Declare the HashSet using Set Interface.
  3. Add elements into the HashSet using the add() method.
  4. Display the HashSet to determine order of elements.
  5. Convert HashSet into Array using toArray() method.
  6. Access elements by index.

Can you index into a set?

1 Answer. A set is just an unordered collection of unique elements. So, an element is either in a set or it isn’t. This means that no element in a set has an index.

How to access element by Index in a set?

In this article we will discuss how to access an element by index in a Set. std::set is an associative container, which internally store elements in a balanced binary search tree and it doesn’t provide random access operator []. Therefore accessing a random element from set by index is little tricky. Suppose we have a set of strings i.e.

How to get an element at specified index from C + + list?

This is now irrelevant, but may be informative nonetheless: std::vector does have random access iterators, so you can perform the equivalent operation in O (1) via the std::advance, std::next if you have C++11 support, the [] operator, or the at () member function: Here’s a get () function that returns the _i th Student in _list.

Is there way to access element at Index in STD?

However, you seems to want the first. So try in C++11: There is no way you can access it in constant time. But you can reach to any element in O (n) time. E.g. This is not a bug in the STD. There is no random access in a std::set. If you need random access by index, you can use std::vector

Why do I need an index in a set?

Sometimes there’s a good reason for needing a set you can index into. I had to implement this functionality recently to support a legacy API which has functions to return the number of items, and the item at an index, so that the caller can enumerate the items.