Closest integer approach is used: the elements of x are rounded to the closest integer. Then check if any solution exists outside of the bounds (and get it back inside the bounds randomly). Finally repair the solution if repetitions exist.
childclosint(r)
mutated vector
a valid ranking
Davendra, D., and Onwubolu, G. (2007). Enhanced differential evolution hybrid scatter search for discrete optimization. In Evolutionary Computation, 2007. CEC 2007. IEEE Congress on (pp. 1156-1162). IEEE.