### arunkumar8202's blog

By arunkumar8202, history, 2 months ago,

Hello community,

I was trying to solve the question 699C Fence Painting during which I came across a interesting bug in C++ compiler which I couldn't figure out.

I tried to submit to same solution using three different versions of C++ and it gave different result on each run.

C++ 14 : The solution got accepted 173550755

C++ 17 : The solution gave wrong answer on testcase 3 173550802

C++ 20 : The solution got runtime error on testcase 3 173550866

MikeMirzayanov will you please look into the matter or clarify if I have made a mistake. Any kind of help will be appreciated.

• -10

 » 2 months ago, # | ← Rev. 2 →   0 .
 » 2 months ago, # |   +15 Your code uses undefined behaviour s.lower_bound({v2[i],0}) could be the end iterator which you are not allowed to dereference.