How to find total number of subarrays with sum atmost k?
Constrains :
-1e4 <= a[i] <= 1e4
1 <= n <= 1e5
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How to find total number of subarrays with sum atmost k?
Constrains :
-1e4 <= a[i] <= 1e4
1 <= n <= 1e5
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We can use sliding window technique to solve the problem.
Here, i and j represent starting and ending points of the sliding window.
Initially i = j = 0.
Now, we will traverse the whole array and try to add elements.
i think this approach won't work for neagitive elements
arr = [2,2,-1] target = 3 it won't count [2,2,-1] in the answer
Oh yes, sorry; in that case it would fail.
Convert the statement to it's equivalent in terms of prefix sums i.e $$$pre_r - pre_l <= k$$$.
Now iterating over $$$r$$$, we need to find number of $$$l$$$ such that $$$pre_l >= pre_r - k$$$, which can be computed using ordered set of all $$$pre_l$$$.
but in this case, I have to iterate on all the prefix values >= pre(r)-k. How you will handle this thing while iterating the array?
use pbds!
You can use pbds or alternatively, compress the values of the prefix sum and use a data structure like segment tree or fenwick tree to count the values.