3.7.133. Latin square

Figure 3.7.36. A partially filled Latin square and a possible completion

A constraint that can be used for modelling the Latin square completion problem. A Latin square of order n is an nΓ—n array in which n distinct numbers in [1,n] are arranged so that each number occurs once in each row and column. The Latin square completion problem is to complete a partially filled Latin square. PartΒ (A) of FigureΒ 3.7.36 gives a partially filled Latin square, while partΒ (B) provides a possible completion. The Latin square completion problem is a pattern that occurs in some applications such that dynamic wavelength routing or sport timetabling.