Lesson 01 Iteration
Lesson 02 Arrays
Lesson 03 Time Complexity
Lesson 04 Counting Elements
FrogRiverOne
MaxCounters
https://app.codility.com/demo/results/trainingG44AKV-9QN/ (66/100)
https://app.codility.com/demo/results/trainingCPR5J2-RYU/
https://app.codility.com/demo/results/trainingJCK8BA-Z3T/ (100/100)
MissingInteger
PermCheck