Respuesta :
a) The problem of crossword has a number of ways to solve. In these, Depth-first-search is the best way to solve the problem.
For this problem, the words which are crossing to each other must have same letters at the cross position. These problem are also known as constraint satisfaction problem.
The table to show the crossword game is as given below.
The hints of words according to the locations in the game are as given:
AFT LASER
ALE LEE
EEL LINE
HEEL SAIL
HIKE SAIL
HIKE SHEET
HOSES STEER
KEEL TIE
KNOT
The numbers 1, 2, 3, 4, 5, 6, 7, and 8 are the positions in the crossword game for the locations of words.
b) For the problem of constraint satisfaction, the value of variable should be letter. This is because, each letter in the game is stored in a separate box and word is made by the collection of letters. This is heuristic approach for solving the game. The diagram to show the flow of process for the completion of word is given in the second image below.

