O'Reilly logo

Mastering C++ Programming by Jeganathan Swaminathan

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Unordered sets

An unordered set works in a manner similar to a set, except that the internal behavior of these containers differs. A set makes use of red-black trees while an unordered set makes use of hash tables. The time complexity of set operations is O( log N) while the time complexity of unordered set operations is O(1); hence, the unordered set tends to be faster than the set.

The values stored in an unordered set are not organized in any particular fashion, unlike in a set, which stores values in a sorted fashion. If performance is the criteria, then an unordered set is a good bet; however, if iterating the values in a sorted fashion is a requirement, then set is a good choice.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required