These are listed in roughly recommended order.
Kattis Programming Challenges Code in the website and submit your code to have it checked - just like CPPLab. Practice in multiple languages (including C++). Nice range of problem difficulties.
Edubits Challenges Code in the website and submit your code to have it checked - just like CPPLab. Practice in multiple languages (including C++). Nice range of problem difficulties.
Codewars
Code in the website and submit your code to have it checked.
Hackerearth coding practice
Code and test in browser. Leans towards more complex problems lots of
260 and beyond problems.
Codechef coding practice
Lots of problems, but not as well curated as some of the other sites.
Advent of Code
Annual set of programming challenges counting December 1–25. The front
page shows the most recent/current year's problems, but you can also view
past events.
Leetcode.com programming practice
Advanced practice. Even the Easy problems require CS260 knowledge.
Reddit Dailyprogrammer
Work on challenge problems proposed by other programmers. Check out solutions created by others.
Project Euler
Math-centric problems.
These resources are focused on programming competitions. They still have lots of programming puzzles, but they tend to emphasize problem solving more than basic programming practice.
US Coding Olympiad
You can make an account and then work your way up from easy problems to hard.
UVA Online Judge
Big lists of problems. A recommended starting point is the category called AOAPC II: Beginning
Algorithm Contests (Second Edition) (Rujia Liu)