diff options
Diffstat (limited to 'library/demos/knightstour.tcl')
| -rw-r--r-- | library/demos/knightstour.tcl | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/library/demos/knightstour.tcl b/library/demos/knightstour.tcl index b5cffa8..11b3b5c 100644 --- a/library/demos/knightstour.tcl +++ b/library/demos/knightstour.tcl @@ -21,7 +21,7 @@ # If you let it repeat then it will choose random start positions # for each new tour. -package require Tk 8.5 +package require Tk # Return a list of accessible squares from a given square proc ValidMoves {square} { @@ -29,7 +29,7 @@ proc ValidMoves {square} { foreach pair {{-1 -2} {-2 -1} {-2 1} {-1 2} {1 2} {2 1} {2 -1} {1 -2}} { set col [expr {($square % 8) + [lindex $pair 0]}] set row [expr {($square / 8) + [lindex $pair 1]}] - if {$row > -1 && $row < 8 && $col > -1 && $col < 8} { + if {$row >= 0 && $row < 8 && $col >= 0 && $col < 8} { lappend moves [expr {$row * 8 + $col}] } } @@ -41,7 +41,7 @@ proc CheckSquare {square} { variable visited set moves 0 foreach test [ValidMoves $square] { - if {[lsearch -exact -integer $visited $test] == -1} { + if {[lsearch -exact -integer $visited $test] < 0} { incr moves } } @@ -55,7 +55,7 @@ proc Next {square} { set minimum 9 set nextSquare -1 foreach testSquare [ValidMoves $square] { - if {[lsearch -exact -integer $visited $testSquare] == -1} { + if {[lsearch -exact -integer $visited $testSquare] < 0} { set count [CheckSquare $testSquare] if {$count < $minimum} { set minimum $count @@ -190,7 +190,7 @@ proc CreateGUI {} { ttk::button $dlg.tf.b1 -text Start -command [list Tour $dlg] ttk::button $dlg.tf.b2 -text Exit -command [list Exit $dlg] set square 0 - for {set row 7} {$row != -1} {incr row -1} { + for {set row 7} {$row >= 0} {incr row -1} { for {set col 0} {$col < 8} {incr col} { if {(($col & 1) ^ ($row & 1))} { set fill tan3 ; set dfill tan4 |