Google Interview Question for Java Developers

Country: United States

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the key here is to imagine instead of flipping the switches in a range (m,n), lets say you always did two operations - flipped switches (0,n) and then (0,m).
Then sort all 2k operations (at the max) by right index of operation (left index is always 0).
When asked about if a light bulb at position x is lit or not, just count operations in the sorted list in which x belongs. i.e. for any flip operation (0, j) such that x<j.
The final state will be number of such operations %2. - depending on how you started it - 0 or 1.

- madhur dixit February 17, 2018 | Flag Reply

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