using vector to solve the problem lands me to TLE but the same logic used by the array got accepted. WHY?
SOLN (by vector): (https://codeforces.com/problemset/submission/1747/184215576). SOLN (by array): (https://codeforces.com/problemset/submission/1747/184217645)
Your debug define seems to be wrong. It uses ifndef. So now on the judge you are debugging the vector each time. I don't know why that is so slow, but at least it's not what you intended.