Why do we need to subtract -1

#1

why do we need to subtract -1 after passing the comparator and why is the output like this on changing the constructor to a>=b instead of a<=b. PLs help with the concept of constructor in this case .

#2

@kunal81198 using comparator on lowerbound just make it behaves like upperbound that’s why -1

#3

Bro can u tell me what does passing this :-
bool compare(int a ,int b){return a>=b;}
comparator function means vs
bool compare(int a ,int b){return a<=b;}
means

#4

@kunal81198
in normal sorting a>b means sort in desc and a<b means sort by inc order
its simple in this case
but in case of lowerbound
comparator are not generally used ( not used once in lowerbound and all)
but still its just for knowledge
a<=b (in the video) just make lower bound behaves like upperbound
ex
1 2 3 4
key =2
lowerbound gives 2
but lowerbound with a<=b comp gives 3
so basically you can use upper bound thats why not used

#5

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