# TADM2E 3.15

From Algorithm Wiki

Init:

k=0

Insert X:

k = k+1; A[X] = k; B[k] = X;

Search X:

return (A[X] < k) and (B[A[X]] == X)

Delete X:

A[B[k]] = A[X]; B[A[X]] = B[k]; k = k-1;

Please note that this data structure doesn't support inserting the same X more than once.