abh123's blog

algorithm behind upperbound in c++
By abh123, 11 years ago, In English

i am using upperbound and lowerbound in c++ regularly but i don't know actual algorithm behind this??? Plzz help..

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11 years ago, # |
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It's a simple binary search.

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11 years ago, # |
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http://www.cplusplus.com/reference/algorithm/upper_bound/

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    11 years ago, # ^ |
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    Actually i m not able to understand this step. std::advance (it,step);

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      11 years ago, # ^ |
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      bcoz this step is linear and this will increase it's complexity..?

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        11 years ago, # ^ |
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        its just equal to it+step in our case, works for O(1)

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          11 years ago, # ^ |
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          It's O ( 1 ) when you have random access iterators, on non random access iterators it has linear complexity.

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11 years ago, # |
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http://www.cplusplus.com/reference/algorithm/lower_bound/

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