Function marked_probability 

pub fn marked_probability(
    oracle_marks: &[usize],
    n_qubits: usize,
) -> QuantumResult<f32>

Total probability mass currently residing on the marked items.

Re-runs the amplification and sums |a_x|² over marked x; useful for asserting that amplitude has been amplified onto the solution subspace.

Errors

Same conditions as grover_search.