alldifferent

alldifferent implements the constraint that all elements are different

Syntax

F = alldifferent(X)

Examples

The following example finds an integer vector with all numbers between 1 and 5.

x = intvar(5,1);
F = [alldifferent(x), 1<=x<=5];
optimize(F)
value(x)

Comments

Since alldifferent is implemented using a big-M approach, it is crucial that all involved variables have explicit bound constraints. Additionally, it only makes numerical sense to apply the operator on integer valued variables.

Applying alldifferent on a variable with \(n\) variables will introduce \(n(n-1)/2\) binary variables.

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