You can do this by binary searching the answer which is checked valid by:

1.making a graph with cost sqrt(|x_j-x_i-L|) — R * b_j and always x_j > x_i.

2.In this graph,find shortest path from x0 to xn (take x0 as a dummy start).

i)if this value is -ve this means the mid(of binary search) is greater than the optimal value.

ii)if +ve this is opposite the above,thus take the necessary steps in else of binary search.

3.Once you get the optimal value you backtrace the waiting pts you took.

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