How to find kth largest element each time where k will vary and array is modifiable. That is you can add new elements to the array array can have duplicates.
for example say array is 10 , 20 , 15.
2nd largest = 15
add 17 to array
array becomes 10 15 17 20
3rd largest = 15
Q <= 10^5.
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You can use PBDS
array can contain duplicates too, i tried it with pdbs but it work for unique elements.
use
less_equalinstead ofless.Thanks a lot. It worked.
Suppose we also want to delete a single element which occurs more than 1 time.
A.erase(x) will delete all x. how to erase just a single x value ?
nilesh8757
You can keep pairs $$$(a_i, id)$$$ in the ordered set ($$$less$$$), where $$$id$$$ is unique for each pair.
Ordered_multiset
Just change less to less_equal
Like this:
But it is giving wrong answer after I perform delete, and I am not able to delete single element from it.
You can use find_by_order to find kth element and add is just insert
You need to write
Thanks.
RetiredPlayer but there is one problem here.
suppose 1 , 3 , 3 , 5 , 7 , 9 , 11
3rd largest = 3
less than 9 = 5 elements
delete(3)
it becomes 1 , 3 , 5 , 7 , 9 , 11
3rd smallest = 5 , but it is showing 3. http://ideone.com/Oessur
No of elements less than 9 are 5 , but it should be 4
after deletion things are not working as it should be.
In the blog above you said about just adding and finding kth element, Ordered_set can't erase element x but it can erase k th element by doing A.erase(A.find_by_order(k))
Try implementing it with fenwick tree. If all the values are less than 1e5 then it becomes relatively easy. If the values can go high then you need to store the queries and process the elements offline so that you can compress the higher values to smaller values.Every element will be compressed to some element <=1e5 as the no. of unique values <= 1e5. Now you can use binary search on fenwick tree !!