Here are my Harvard CS50x 2018 problem set solutions.
Link to pset1: https://docs.cs50.net/2018/x/psets/1/pset1.html
Link to pset2: https://docs.cs50.net/2018/x/psets/2/pset2.html
Link to pset3: https://docs.cs50.net/2018/x/psets/3/pset3.html
Link to pset4: https://docs.cs50.net/2018/x/psets/4/pset4.html
Link to pset5: https://docs.cs50.net/2018/x/psets/5/pset5.html
Link to pset6: https://docs.cs50.net/2018/x/psets/6/pset6.html
Link to pset7: https://docs.cs50.net/2018/x/psets/7/pset7.html
Link to pset8: https://docs.cs50.net/2018/x/psets/8/pset8.html