On windows7 Code::Blocks20.03, Histogram program can't do well!

[CodeBeginnerCn]

Cpp-Tutorial-Samples/Histogram

Dear sinairv

When I run the code in Histogram on code::Blocks, It act not like what I expected. I don't know what happen to it.
When I copy the code from the github file ,the action went well .

Here is editor

Here is the result.

I can't explain why the value column, is not 18 20 but 181 and 201.

I install Code::Blocks using codeblocks-20.03mingw-setup.exe file from https://nchc.dl.sourceforge.net/project/codeblocks/Binaries/20.03/Windows/codeblocks-20.03mingw-setup.exe

It's my pleasure if you are willing to explain it !

Thank you!