Use std::unique_ptr instead of new

[arukuka]

Summary

• Use smart pointer instead of handling raw pointer

Purpose

• prevent memory leak

Contents

• bb708fa Use std::unique_ptr instead of new

Testing Methods Performed

• Run progress_demo.py 3~5 times with N=10,000, valgrind --tool=massif when launching CC
• Run CC small, medium test

[mdonaka]

Thanks for the great changes!
This is a minute thing, but please check two points.

[arukuka]

@mdonaka I changed code, and check that small, medium test are passed at local.
Please review again.