--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rule.js	Sun Sep 07 00:19:00 2014 +0300
@@ -0,0 +1,187 @@
+"use strict";
+
+var board = {};
+board.create = function() {
+    var brd = [];
+    for (var i = 0; i < 4; i++) {
+        brd[i] = [];
+        for (var j = 0; j < 4; j++) {
+            brd[i][j] = 0;
+        }
+    }
+    return brd;
+}
+board.copy = function(from, to) {
+    for (var i = 0; i < 4; i++) {
+        for (var j = 0; j < 4; j++) {
+            to[i][j] = from[i][j];
+        }
+    }
+}
+board.freeCnt = function(brd) {
+    var cnt = 0;
+    for (var i = 0; i < 4; i++) {
+        for (var j = 0; j < 4; j++) {
+            if (brd[i][j] === 0)
+                cnt++;
+        }
+    }
+    return cnt;
+}
+board.gameOver = function(brd) {
+    if (board.freeCnt(brd) > 0)
+        return false;
+    for (var i = 0; i < 4; i++) {
+        for (var j = 0; j < 3; j++) {
+            if (brd[i][j] === brd[i][j+1])
+                return false;
+        }
+    }
+    for (var j = 0; j < 4; j++) {
+        for (var i = 0; i < 3; i++) {
+            if (brd[i][j] === brd[i+1][j])
+                return false;
+        }
+    }
+    return true;
+}
+board.putRandom = function(brd) {
+    var cnt = board.freeCnt(brd);
+    cnt = Math.floor(Math.random() * cnt)+1;
+    for (var i = 0; i < 4 && cnt > 0; i++) {
+        for (var j = 0; j < 4 && cnt > 0; j++) {
+            if (brd[i][j] !== 0)
+                continue;
+            if (cnt === 1)
+                brd[i][j] = (Math.random() > .9) ? 2 : 1;
+            cnt--;
+        }
+    }
+}
+/* http://www.reddit.com/r/2048/comments/214njx/highest_possible_score_for_2048_warning_math */
+var boardScoreTbl = [0];
+for (var i = 1, exp = 2; i < 16; i++, exp *= 2) {
+    boardScoreTbl[i] = (i-1)*exp;
+}
+board.score = function(brd) {
+    var score = 0;
+    var max = 0;
+    for (var i = 0; i < 4; i++) {
+        for (var j = 0; j < 4; j++) {
+            var val = brd[i][j];
+            score += boardScoreTbl[val];
+            if (max < val)
+                max = val;
+        }
+    }
+    return {score: score, max: Math.pow(2, max)};
+}
+
+board.row = {};
+board.row.init = function() {
+    return {stack: [], curr: 0};
+}
+board.row.push = function(state, val) {
+    if (val === 0)
+        return;
+    if (state.curr === 0) {
+        state.curr = val;
+        return;
+    }
+    if (state.curr === val) {
+        state.stack.push(state.curr+1);
+        state.curr = 0;
+    } else {
+        state.stack.push(state.curr);
+        state.curr = val;
+    }
+}
+board.row.finish = function(state) {
+    if (state.curr !== 0)
+        state.stack.push(state.curr);
+}
+board.move = {};
+board.move.up = function(brd) {
+    var updated = false;
+    for (var j = 0; j < 4; j++) {
+        var state = board.row.init();
+        for (var i = 0; i < 4; i++) {
+            board.row.push(state, brd[i][j]);
+        }
+        board.row.finish(state);
+        for (var i = 0; i < state.stack.length; i++) {
+            if (brd[i][j] !== state.stack[i])
+                updated = true;
+            brd[i][j] = state.stack[i];
+        }
+        for (; i < 4; i++) {
+            if (brd[i][j] !== 0)
+                updated = true;
+            brd[i][j] = 0;
+        }
+    }
+    return updated;
+};
+board.move.down = function(brd) {
+    var updated = false;
+    for (var j = 0; j < 4; j++) {
+        var state = board.row.init();
+        for (var i = 3; i >= 0; i--) {
+            board.row.push(state, brd[i][j]);
+        }
+        board.row.finish(state);
+        for (var i = 0; i < state.stack.length; i++) {
+            if (brd[3-i][j] !== state.stack[i])
+                updated = true;
+            brd[3-i][j] = state.stack[i];
+        }
+        for (; i < 4; i++) {
+            if (brd[3-i][j] !== 0)
+                updated = true;
+            brd[3-i][j] = 0;
+        }
+    }
+    return updated;
+};
+board.move.left = function(brd) {
+    var updated = false;
+    for (var i = 0; i < 4; i++) {
+        var state = board.row.init();
+        for (var j = 0; j < 4; j++) {
+            board.row.push(state, brd[i][j]);
+        }
+        board.row.finish(state);
+        for (var j = 0; j < state.stack.length; j++) {
+            if (brd[i][j] !== state.stack[j])
+                updated = true;
+            brd[i][j] = state.stack[j];
+        }
+        for (; j < 4; j++) {
+            if (brd[i][j] !== 0)
+                updated = true;
+            brd[i][j] = 0;
+        }
+    }
+    return updated;
+};
+board.move.right = function(brd) {
+    var updated = false;
+    for (var i = 0; i < 4; i++) {
+        var state = board.row.init();
+        for (var j = 3; j >= 0; j--) {
+            board.row.push(state, brd[i][j]);
+        }
+        board.row.finish(state);
+        for (var j = 0; j < state.stack.length; j++) {
+            if (brd[i][3-j] !== state.stack[j])
+                updated = true;
+            brd[i][3-j] = state.stack[j];
+        }
+        for (; j < 4; j++) {
+            if (brd[i][3-j] !== 0)
+                updated = true;
+            brd[i][3-j] = 0;
+        }
+    }
+    return updated;
+};