O(1) : No.of perfect squares between given range

Source : quora >>>
https://www.quora.com/How-can-I-find-out-number-of-perfect-squares-in-a-given-range-of-numbers-in-c-c++-programming-in-least-time

Formula : 1 + (floor (sqrt (upper bound) ) - (ceiling ( sqrt (lower bound) )


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