array of vector is faster than vector of vector for storing adjaceny list?

Правка en1, от diradon, 2020-06-15 19:13:58

Hi all, I recently came across an issue that I am unable to comprehend. While solving problem 1337C, I used the same code twice except using a vector<vector<int> > adj(n) in 83595937 and vector<int> a[n] in 83693762. For some reason, the first submission timed out and the second one passed. I thought maybe it has something to do with the fact that vectors aren't preallocating the proper space but that shouldn't be the case as I am mentioning the size n while declaring the vector of vector as well. I searched for this problem on the internet but the discussion is almost always about vector vs arrays and not 2D containers. Thanks for the help!

Теги 2d vector, #array, #tle, speed

История

 
 
 
 
Правки
 
 
  Rev. Язык Кто Когда Δ Комментарий
en2 Английский diradon 2020-06-15 19:32:50 158
en1 Английский diradon 2020-06-15 19:13:58 756 Initial revision (published)