flatten_2d_vector

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251. Flatten 2D Vector (Medium)

Related Topics

[Design]

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Hints

Hint 1

How many variables do you need to keep track?

Hint 2

Two variables is all you need. Try with x and y.

Hint 3

Beware of empty rows. It could be the first few rows.

Hint 4

To write correct code, think about the invariant to maintain. What is it?

Hint 5

The invariant is x and y must always point to a valid point in the 2d vector. Should you maintain your invariant ahead of time or right when you need it?

Hint 6

Not sure? Think about how you would implement hasNext(). Which is more complex?

Hint 7

Common logic in two different places should be refactored into a common method.