I have recently published solutions which I wrote in C++ for many of the problems from the book "Cracking the Coding Interview: 150 Programming Interview Questions and Solutions", 4th edition. They can be found here.
These solutions were very carefully written and tested. Whenever possible, I have tested results from sophisticated approaches to a problem against more elementary ones such as brute force. This means that most problems are solved in at least two different ways, and results from different techniques are compared to enhance the trust on their correctness.
Corrections and suggestions for improvement will be very much appreciated. Feel free to post a comment below with questions you may have. Enjoy! :-)