I solved it using segment tree. Can it be solved using BIT, Has anyone done that ?
http://www.spoj.pl/problems/BRCKTS/
http://www.spoj.pl/problems/BRCKTS/
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Can u tel me if I use segment tree to solve this question then on which basis should i build the tree..?
every node in the tree should have the what is its need of brackets. For example you can maintain a variable called balance for which you have the following:
balance = 0 — the interval to which the node corresponds is balanced balance = x (x>0) — the interval needs x closing brackets balance = x (x<0) — the interval needs x opening brackets
You should make the changes in the update function and your query function would simply check if the balance of the root is 0
Update: this balance thing should be implemented by separating the needs for every node this means that you must keep needOpening and needClosing for every node