Contest 1 based on arrays
link to contest : https://codeforces.com/contestInvitation/4377116e5bd9466d83d1f6e6cf2411299e088592
Link to Editorial : https://youtu.be/hEKLwM9qXPc
Contest 2 based on Number Theory
Link to contest : https://codeforces.com/contestInvitation/57cb7c90836ae129ab29d3bda0c850f8fcaa23d8
Link to editorial : https://youtu.be/J7N-2a4wv-0
Contest 3 based on Strings
Link to contest : https://codeforces.com/contestInvitation/c1e985a9cc2bdcc0ae980029870384526ade7035
Link to editorial : https://youtu.be/0S6EvRbMkKo
Contest 4 based on STL
Link to contest : https://codeforces.com/contestInvitation/6134b80446ec8fe60c7a579401850487b4dd60f4
Link to editorial : https://youtu.be/qwdpu09wF3U
Contest 5 based on Bit-masking
Link to contest : https://codeforces.com/contestInvitation/2f1acb4a733c9ee47ac3974001e2eb815aa792b4
Link to editorial : https://youtu.be/o_D7x2cwnOo
Contest 6 based on Binary-Search
Link to contest : https://codeforces.com/contestInvitation/d35aa6eeecc2893eb6e44b66b106205f67c03d28
Link to editorial : https://youtu.be/OjEqOminJew
Contest 7 prized contest mix problems
Link to contest : https://codeforces.com/contestInvitation/731604873168614ef132ac74e851305f79fc9d87
Link to editorial of A : https://youtu.be/lebxb3adlhY
Link to editorial of B : https://youtu.be/CwKhKuYEvZo
Link to editorial of C : https://youtu.be/Hqn8XEW3EQI
Link to editorial of D : https://youtu.be/Di7R4ic6YIs
Link to editorial of E : https://youtu.be/XuQnCByZHAQ