for this problem 1237B - Сбалансированный тоннель , This is my approach 309018105
I am starting from behind in second array and if a Car has moved backwards that is its position in coming out array is greater that coming in array then make it a victim and then for all cars coming before it check if they have crossed it until we find new victim and update it too and check for them too.
My thinking is that any car that has been overtaken will go back unless it overtakes someone else. So there is always a victim and so it should work. But it doesn't is there a case i am missing because in 4th test case i am missing the answer by big difference.
I have solved the problem with brute force but it is ugly 309016497, so was wondering why this victim approach is not working.
Think about this test case:
4
1 2 3 4
1 3 2 4
the answer is 1 but your code gives 0. Why? ask yourself you will get your answer. :)
Problem is your current victim is not the worst victim.
your first code found an victim and count its first car that go earlier than it,and if right after that is another victim your code just jump to it,did not fully checking previous,then you must check fully it,because one victim can be overtaken by some cars , not only one