From 775398f4568cf76b35d4fdbf207861c7dc4aaf90 Mon Sep 17 00:00:00 2001
From: Reza Behzadan <rbehzadan@gmail.com>
Date: Fri, 29 May 2020 10:19:18 +0430
Subject: [PATCH] add keys 'a' and 's' for showing board options

---
 sudoku/sudoku.lua   | 37 +++++++++++++++++++++++++++++++++++++
 ui/sudokucanvas.lua | 22 ++++++++++++++++++++++
 2 files changed, 59 insertions(+)

diff --git a/sudoku/sudoku.lua b/sudoku/sudoku.lua
index e2077a6..053e584 100644
--- a/sudoku/sudoku.lua
+++ b/sudoku/sudoku.lua
@@ -78,6 +78,43 @@ function sudoku.checkBoard(board)
     return ok, isComplete, conflictList
 end
 
+function sudoku.calCellValidOptions(board, x, y)
+    if board[x][y] ~= 0 then return {} end
+    local u = {}
+    local v = {}
+    for i = 1, 9 do
+        if board[x][i] ~= 0 then table.insert(u, board[x][i]) end
+        if board[i][y] ~= 0 then table.insert(u, board[i][y]) end
+    end
+    local dx = math.floor((x - 1) / 3) * 3
+    local dy = math.floor((y - 1) / 3) * 3
+    for i = 1, 3 do
+        for j = 1, 3 do
+            local a = board[i+dx][j+dy]
+            if a ~= 0 then table.insert(u, a) end
+        end
+    end
+    for i = 1, 9 do
+        local found = false
+        for _, elm in ipairs(u) do
+            if elm == i then found = true; break end
+        end
+        if not found then table.insert(v, i) end
+    end
+    return v
+end
+
+function sudoku.buildSearchSpave(board)
+    local s = {}
+    for i = 1, 9 do
+        s[i] = {}
+        for j = 1, 9 do
+            s[i][j] = sudoku.calCellValidOptions(board, i, j)
+        end
+    end
+    return s
+end
+
 sudoku.cloneBoard = utils.cloneBoard
 sudoku.createEmptyBoard = utils.createEmptyBoard
 sudoku.loadBoard = utils.loadBoard
diff --git a/ui/sudokucanvas.lua b/ui/sudokucanvas.lua
index 26e5c33..db78c37 100644
--- a/ui/sudokucanvas.lua
+++ b/ui/sudokucanvas.lua
@@ -1,6 +1,24 @@
 SudokuCanvas = {}
 SudokuCanvas.__index = SudokuCanvas
 
+function showValidOptionsForCurrentCell(self, x, y)
+    local s = sudoku.calCellValidOptions(self.board[2], y, x)
+    for num = 1, 9 do
+        self.smallNumbers[x][y][num].enabled = false
+    end
+    for _, num in ipairs(s) do
+        self.smallNumbers[x][y][num].enabled = true
+    end
+end
+
+function showValidOptionsForAllCells(self)
+    for x = 1, 9 do
+        for y = 1, 9 do
+            showValidOptionsForCurrentCell(self, x, y)
+        end
+    end
+end
+
 local function selectSmallNumbersFont(cellSize)
     local fntSize = 65
     local margin = 0
@@ -363,6 +381,10 @@ function SudokuCanvas:keypressed(key)
             self.board[2][y][x] = self.board[3][y][x]
             mode = "big"
         end
+    elseif key == "s" then
+        showValidOptionsForCurrentCell(self, x, y)
+    elseif key == "a" then
+        showValidOptionsForAllCells(self)
     end
     self.cursor.x = x
     self.cursor.y = y