analyser_test.go

package sudoku

import "testing"

func TestNumSolutions(t *testing.T) {
	// “Easy” difficulty with a single solution
	puz := Puzzle{
		'2', ' ', ' ', '6', '3', ' ', ' ', '1', ' ',
		' ', '5', '1', ' ', '2', ' ', '7', '9', '3',
		'4', ' ', '3', '1', '9', '7', '5', ' ', ' ',
		' ', ' ', ' ', ' ', ' ', '9', ' ', '3', '2',
		' ', '6', '5', ' ', '7', ' ', '1', '4', ' ',
		'1', '3', ' ', '8', ' ', ' ', ' ', ' ', ' ',
		' ', ' ', '9', '3', '6', '2', '4', ' ', '7',
		'3', '7', '6', ' ', '8', ' ', '2', '5', ' ',
		' ', '2', ' ', ' ', '5', '1', ' ', ' ', '9'}
	expect := 1
	solutions := puz.NumSolutions()
	if solutions != expect {
		t.Errorf("incorrect return from NumSolutions(): expected %v, got %v", expect, solutions)
	}

	// “Tricky” difficulty with a single solution
	puz = Puzzle{
		' ', ' ', '3', ' ', '5', ' ', '2', ' ', ' ',
		'2', ' ', ' ', '7', ' ', '6', ' ', ' ', '9',
		'7', ' ', ' ', ' ', ' ', ' ', ' ', ' ', '4',
		' ', '2', ' ', '8', ' ', '1', ' ', '6', ' ',
		' ', ' ', '9', '6', ' ', '2', '4', ' ', ' ',
		' ', '4', ' ', '3', ' ', '5', ' ', '2', ' ',
		'4', ' ', ' ', ' ', ' ', ' ', ' ', ' ', '8',
		'3', ' ', ' ', '4', ' ', '8', ' ', ' ', '2',
		' ', ' ', '5', ' ', '1', ' ', '3', ' ', ' '}
	solutions = puz.NumSolutions()
	if solutions != expect {
		t.Errorf("incorrect return from NumSolutions(): expected %v, got %v", expect, solutions)
	}

	// Blank puzzle, multiple solutions
	puz = Puzzle{
		' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
		' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
		' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
		' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
		' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
		' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
		' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
		' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ',
		' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '}
	solutions = puz.NumSolutions()
	if solutions <= 1 {
		t.Errorf("incorrect return from NumSolutions() for blank puzzle: expected multiple, got %v", solutions)
	}

	// Golang challenge 8 sample puzzle, multiple solutions
	puz = Puzzle{
		'1', ' ', '3', ' ', ' ', '6', ' ', '8', ' ',
		' ', '5', ' ', ' ', '8', ' ', '1', '2', ' ',
		'7', ' ', '9', '1', ' ', '3', ' ', '5', '6',
		' ', '3', ' ', ' ', '6', '7', ' ', '9', ' ',
		'5', ' ', '7', '8', ' ', ' ', ' ', '3', ' ',
		'8', ' ', '1', ' ', '3', ' ', '5', ' ', '7',
		' ', '4', ' ', ' ', '7', '8', ' ', '1', ' ',
		'6', ' ', '8', ' ', ' ', '2', ' ', '4', ' ',
		' ', '1', '2', ' ', '4', '5', ' ', '7', '8'}
	solutions = puz.NumSolutions()
	if solutions <= 1 {
		t.Errorf("incorrect return from NumSolutions() for golang-8 puzzle: expected multiple, got %v", solutions)
	}
}