modify the program to make it more concise.
Q18_10. Learnt a lot through this program.
nothing special just make the code tight.
make the program makes more sense and more robust
this might be an important question to prepare, definitely A class question
Q18_07
update the program with more unordered_map, for and for_each usage
iterative attempt but failed. change the property of h and w from private to public
adding a small script for items multiplication without using multiplier
questions found from website: 1. multiple two integer values without using * operator 2. finding the most frequent number within a number array