construct/mc all interval
construct/mc all interval: a task in MathConstructOptimize-Envs-harbor (Harbor dataset). An all-interval series of size 20 is a permutation x 0..19 of 0..19 such that the absolute differences d i = x i+1 - x i (i = 0..18) form a permutation of 1..19.
The task
An all-interval series of size 20 is a permutation x[0..19] of 0..19 such that the absolute differences d[i] = |x[i+1] - x[i]| (i = 0..18) form a permutation of 1..19.