西洋棋AI | JavaScript 程式專案

{"id":151403,"student_id":1404,"content":"\n// 第一週，評估函數的教學\nfunction evaluation (grid) {\n    var points = 0;\n    for (var x=0; x\u003c8; x++) {\n        for (var y=0; y\u003c8; y++) {\n            if (grid[x][y] == 'b_pawn') points += 10;\n            if (grid[x][y] == 'b_knight') points += 30;\n            if (grid[x][y] == 'b_bishop') points += 30;\n            if (grid[x][y] == 'b_rook') points += 50;\n            if (grid[x][y] == 'b_queen') points += 300;\n            if (grid[x][y] == 'b_king') points += 1000;\n\n            if (grid[x][y] == 'w_pawn') points -= 10;\n            if (grid[x][y] == 'w_knight') points -= 30;\n            if (grid[x][y] == 'w_bishop') points -= 30;\n            if (grid[x][y] == 'w_rook') points -= 50;\n            if (grid[x][y] == 'w_queen') points -= 300;\n            if (grid[x][y] == 'w_king') points -= 1000;\n        }   \n    }\n    return points;\n};\n\nfunction AI () {\n    var startTime = Date.now();\n    \n    // 第一週，評估函數的教學\n    // var bestPoint = -Infinity;\n    // var fromX, fromY, toX, toY;\n    // for (var x=0; x\u003c8; x++) {\n    //     for (var y=0; y\u003c8; y++) {\n    //         Chess.getSteps(x, y).forEach(function (pos) {\n    //             Chess.move(x, y, pos.x, pos.y);\n    //             var points = evaluation(grid);\n    //             if (points \u003e bestPoint) {\n    //                 bestPoint = points;\n    //                 fromX = x;\n    //                 fromY = y;\n    //                 toX = pos.x;\n    //                 toY = pos.y;\n    //             }\n    //             Chess.undo();\n    //         });\n    //     }    \n    // };\n    // Chess.move(fromX, fromY, toX, toY);\n    \n    \n    // 第二週，極大極小演算法教學\n    // function minimax (grid, turn, depth) {\n    //     if (depth === 0) {\n    //         return { points: evaluation(grid) }\n    //     }\n        \n    //     var bestPoint = turn == 'b' ? -Infinity : +Infinity;\n    //     var fromX, fromY, toX, toY;\n        \n    //     for (var x=0; x\u003c8; x++) {\n    //         for (var y=0; y\u003c8; y++) {\n    //             getSteps(x, y).forEach(function (pos) {\n                   \n    //               Chess.move(x, y, pos.x, pos.y);\n                   \n    //               var result = minimax(grid, turn === 'b' ? 'w' : 'b', depth - 1);\n                   \n    //               if (turn == 'b' \u0026\u0026 result.points \u003e bestPoint) {\n    //                   bestPoint = result.points;\n    //                   fromX = x;\n    //                   fromY = y;\n    //                   toX = pos.x;\n    //                   toY = pos.y;\n    //               }\n    //               if (turn == 'w' \u0026\u0026 result.points \u003c bestPoint) {\n    //                   bestPoint = result.points;\n    //                   fromX = x;\n    //                   fromY = y;\n    //                   toX = pos.x;\n    //                   toY = pos.y;\n    //               }\n                   \n    //               Chess.undo();\n                    \n    //             });\n    //         }    \n    //     }\n        \n    //     return {\n    //         fromX: fromX,\n    //         fromY: fromY,\n    //         toX: toX,\n    //         toY: toY,\n    //         points: bestPoint\n    //     }\n    // }\n    \n    // 第三週，從極大極小值演算法加上剪枝，程式碼增加不超過十行，但概念講個一節課都需要花時間搞懂\n    function alphabeta (grid, alpha, beta, turn, depth) {\n        if (depth === 0) {\n            return { points: evaluation(grid) }\n        }\n        \n        var bestPoint = turn == 'b' ? -Infinity : +Infinity;\n        var fromX, fromY, toX, toY;\n        \n        for (var x=0; x\u003c8; x++) {\n            for (var y=0; y\u003c8; y++) {\n                let steps = getSteps(x, y);\n                for (var i=0; i\u003csteps.length; i++) {\n                   var pos = steps[i];\n                   \n                   Chess.move(x, y, pos.x, pos.y);\n                   \n                   var result = alphabeta(grid, alpha, beta, turn === 'b' ? 'w' : 'b', depth - 1);\n                   \n                   if (turn == 'b' \u0026\u0026 result.points \u003e bestPoint) {\n                       bestPoint = result.points;\n                       fromX = x;\n                       fromY = y;\n                       toX = pos.x;\n                       toY = pos.y;\n                       \n                       alpha = bestPoint;\n                       if (bestPoint \u003e= beta) {\n                           Chess.undo();\n                           return { points: bestPoint }\n                       }\n                   }\n                   if (turn == 'w' \u0026\u0026 result.points \u003c bestPoint) {\n                       bestPoint = result.points;\n                       fromX = x;\n                       fromY = y;\n                       toX = pos.x;\n                       toY = pos.y;\n                       \n                       beta = bestPoint;\n                       if (bestPoint \u003c= alpha) {\n                           Chess.undo();\n                           return { points: bestPoint }\n                       }\n                   }\n                   \n                   \n                   Chess.undo();\n                    \n                };\n            }    \n        }\n        \n        return {\n            fromX: fromX,\n            fromY: fromY,\n            toX: toX,\n            toY: toY,\n            points: bestPoint\n        }\n    }\n    \n    // var result = minimax(grid, 'b', 4);\n    var result = alphabeta(grid, -Infinity, +Infinity, 'b', 3);\n    Chess.move(result.fromX, result.fromY, result.toX, result.toY);\n\n    console.log((Date.now() - startTime)/1000 + 's');\n}\n\n\n","created_at":"2020-05-23T15:30:44.118+08:00","updated_at":"2020-05-23T15:33:13.091+08:00","name":"西洋棋AI","language":"javascript","screenshot":{"url":"https://cdn5.koding.school/uploads/project/screenshot/151403/c19ba827d564262a82f62357f6f829f0.jpg"},"parent_id":2,"plugin":"var Chess = (function () {\n    \n    let instance = {\n        // w、b 表示當前回合下棋的顏色，遊戲開始白色先下\n        turn: 'w',\n    };\n    \n    // 選定移動的格子\n    let focusOn = {\n        x: undefined,\n        y: undefined,\n    }\n    \n    // 紀錄所有的移動，在 undo 返回時調用\n    let logs = [];\n    \n    // 存放棋盤格子角色\n    let board = [[], [], [], [], [], [], [], []]; \n    \n    // 存放棋子角色\n    let chessman = [[], [], [], [], [], [], [], []];\n    \n    // 角色造型編號與名稱對照表\n    let chessmanCostumeIds = [\n        'b_rook', // 0\n        'b_knight', // 1\n        'b_bishop', // 2\n        'b_king', // 3\n        'b_queen', // 4\n        'b_pawn', // 5\n        'w_rook', // 6\n        'w_knight', // 7\n        'w_bishop', // 8\n        'w_king', // 9\n        'w_queen', // 10\n        'w_pawn', // 11\n    ];\n    \n    // 表示當前棋子的位置\n    let grid = [\n        ['b_rook',   'b_pawn', '', '', '', '', 'w_pawn', 'w_rook'],\n        ['b_knight', 'b_pawn', '', '', '', '', 'w_pawn', 'w_knight'],\n        ['b_bishop', 'b_pawn', '', '', '', '', 'w_pawn', 'w_bishop'],\n        ['b_king',   'b_pawn', '', '', '', '', 'w_pawn', 'w_king'],\n        ['b_queen',  'b_pawn', '', '', '', '', 'w_pawn', 'w_queen'],\n        ['b_bishop', 'b_pawn', '', '', '', '', 'w_pawn', 'w_bishop'],\n        ['b_knight', 'b_pawn', '', '', '', '', 'w_pawn', 'w_knight'],\n        ['b_rook',   'b_pawn', '', '', '', '', 'w_pawn', 'w_rook'],\n    ];\n    \n    // 初始化棋盤格子\n    for (let x = 0; x \u003c 8; x++) {\n        for (let y = 0; y \u003c 8; y++) {\n            let block = createSprite(['dark.png', 'light.png', 'red.png']);\n            block.x = 120 + 50*x + 25;\n            block.y = 40 + 50*y + 25;\n            block.scale = .5;\n            board[x][y] = block;\n            \n            block.on('click', function () {\n                if (focusOn.x === undefined \u0026\u0026 grid[x][y][0] === instance.turn) {\n                    focusOn.x = x;\n                    focusOn.y = y;\n                    // 將可移動到的格子上色\n                    getSteps(x, y).forEach((pos) =\u003e {\n                        board[pos.x][pos.y].costumeId = 2; // 上紅色\n                    });\n                } else {\n                    if (board[x][y].costumeId === 2) {\n                        move(focusOn.x, focusOn.y, x, y);\n                        \n                         // 暫時插在這裏\n                        setTimeout(function() {\n                            if (window.AI) AI();\n                        }, 500);\n                    }\n                    focusOn.x = undefined;\n                    focusOn.y = undefined;\n                    clearBoardColor();\n                    \n                    \n                    \n                }\n            });\n            \n            \n        }\n    }\n    clearBoardColor(); // 重置棋盤的顏色\n    \n    // 初始化棋盤角色\n    for (let x = 0; x \u003c 8; x++) {\n        for (let y = 0; y \u003c 8; y++) {\n            let costumes = [];\n            for (var i=0; i\u003cchessmanCostumeIds.length; i++) {\n                costumes.push(chessmanCostumeIds[i] + '.png');\n            }\n            let piece = createSprite(costumes);\n            piece.scale = .2;\n            piece.x = 120 + 50*x + 25;\n            piece.y = 40 + 50*y + 25;\n            chessman[x][y] = piece;\n        }\n    }\n    \n    // 監聽 grid 二維陣列的狀態並即時反應在遊戲畫面上\n    forever(function() {\n        for (let x = 0; x \u003c 8; x++) {\n            for (let y = 0; y \u003c 8; y++) {\n                if (grid[x][y] !== '') {\n                    chessman[x][y].hidden = false;\n                    chessman[x][y].costumeId = chessmanCostumeIds.indexOf(grid[x][y]);\n                } else {\n                    chessman[x][y].hidden = true;\n                }\n            }\n        }\n    });\n    \n    // 清除棋盤上提示的顏色格子\n    function clearBoardColor () {\n        for (let x = 0; x \u003c 8; x++) {\n            for (let y = 0; y \u003c 8; y++) {\n                board[x][y].costumeId = (x + y)%2;\n            }\n        }\n    }\n    \n    // 返回 x, y 格子的棋子能到達的所有格子位置\n    function getSteps(x, y) {\n        if (grid[x][y] == undefined || grid[x][y][0] !== instance.turn) return [];\n    \n        if (grid[x][y] == 'b_rook' || grid[x][y] == 'w_rook') return rookSteps(x, y);\n        if (grid[x][y] == 'b_knight' || grid[x][y] == 'w_knight') return knightSteps(x, y);\n        if (grid[x][y] == 'b_bishop' || grid[x][y] == 'w_bishop') return bishopSteps(x, y);\n        if (grid[x][y] == 'b_king' || grid[x][y] == 'w_king') return kingSteps(x, y);\n        if (grid[x][y] == 'b_queen' || grid[x][y] == 'w_queen') return queenSteps(x, y);\n        if (grid[x][y] == 'b_pawn' || grid[x][y] == 'w_pawn') return pawnSteps(x, y);\n        return [];\n    }\n    \n    function knightSteps (x, y) {\n        let result = [];\n        [\n            {x: 2, y: 1},\n            {x: -2, y: -1},\n            {x: 1, y: 2},\n            {x: -1, y: -2},\n            {x: -1, y: 2},\n            {x: 1, y: -2},\n            {x: -2, y: 1},\n            {x: 2, y: -1},\n        ].forEach((pos) =\u003e {\n            let xx = pos.x + x;\n            let yy = pos.y + y;\n            if (xx \u003c 0 || yy \u003c 0 || xx \u003e= 8 || yy \u003e= 8) return;\n            if (grid[xx][yy][0] === instance.turn) return;\n            result.push({ x: xx, y: yy });\n        });\n        return result;\n    }\n    \n    function bishopSteps (x, y) {\n        return lineSteps(x, y, 1, -1)\n        .concat(lineSteps(x, y, -1, 1))\n        .concat(lineSteps(x, y, 1, 1))\n        .concat(lineSteps(x, y, -1, -1))\n    }\n    \n    function rookSteps (x, y) {\n        return lineSteps(x, y, 0, -1)\n        .concat(lineSteps(x, y, 0, 1))\n        .concat(lineSteps(x, y, 1, 0))\n        .concat(lineSteps(x, y, -1, 0))\n    }\n    \n    function queenSteps (x, y) {\n        return rookSteps(x, y).concat(bishopSteps(x, y));\n    }\n    \n    function kingSteps (x, y) {\n        let result = [];\n        [\n            { x: -1, y: -1 },\n            { x: 0, y: -1 },\n            { x: 1, y: -1 },\n            { x: -1, y: 0 },\n            { x: 1, y: 0 },\n            { x: -1, y: 1 },\n            { x: 0, y: 1 },\n            { x: 1, y: 1 }\n        ].forEach((pos) =\u003e {\n                let xx = pos.x + x;\n                let yy = pos.y + y;\n                if (xx \u003c 0 || yy \u003c 0 || xx \u003e= 8 || yy \u003e= 8) return;\n                if (grid[xx][yy][0] === instance.turn) return;\n                result.push({\n                    x: xx, y: yy\n                });\n            });\n        return result;\n    }\n    \n    \n    function pawnSteps (x, y) {\n        let result = [];\n        if (instance.turn === 'b') {\n            if (grid[x][y + 1] === '') {\n                result.push({x: x, y: y + 1});\n                if (y == 1 \u0026\u0026 grid[x][y + 2] === '') result.push({x: x, y: y + 2});\n            }\n            if (x + 1 \u003c= 7 \u0026\u0026 grid[x + 1][y + 1][0] == 'w') result.push({x: x+1, y: y + 1});\n            if (x - 1 \u003e= 0 \u0026\u0026 grid[x - 1][y + 1][0] == 'w') result.push({x: x-1, y: y + 1});\n        } else {\n            if (grid[x][y - 1] === '') {\n                result.push({x: x, y: y - 1});\n                if (y == 6 \u0026\u0026 grid[x][y - 2] === '') result.push({x: x, y: y - 2});\n            }\n            if (x + 1 \u003c= 7 \u0026\u0026 grid[x + 1][y - 1][0] == 'b') result.push({x: x+1, y: y - 1});\n            if (x - 1 \u003e= 0 \u0026\u0026 grid[x - 1][y - 1][0] == 'b') result.push({x: x-1, y: y - 1});\n        }\n        return result;\n    }\n    \n    function lineSteps (x, y, offsetX, offsetY) {\n        let result = [];\n        for (let i = 1; i \u003c 8; i++) {\n            let xx = x + i*offsetX;\n            let yy = y + i*offsetY;\n            if (xx \u003c 0 || yy \u003c 0 || xx \u003e= 8 || yy \u003e= 8) break;\n            if (grid[xx][yy] !== '') {\n                if (grid[xx][yy][0] !== instance.turn) {\n                    result.push({ x: xx, y: yy });\n                }\n                break;\n            }\n            result.push({ x: xx, y: yy });\n        }\n        return result;\n    }\n    \n    // 角色移動\n    function move (fromX, fromY, toX, toY) {\n        logs.push(['move', fromX, fromY, toX, toY, grid[toX][toY]]);\n        grid[toX][toY] = grid[fromX][fromY];\n        grid[fromX][fromY] = '';\n        instance.turn = instance.turn === 'b' ? 'w' : 'b';\n    }\n    \n    // 返回上一個動作\n    function undo () {\n        if (logs.length \u003c= 0) return;\n        let action = logs.pop();\n        if (action[0] === 'move') {\n            grid[action[1]][action[2]] = grid[action[3]][action[4]];\n            grid[action[3]][action[4]] = action[5]; \n        }\n        instance.turn = instance.turn === 'b' ? 'w' : 'b';\n    }\n    \n    // 開放介面\n    instance.grid = grid;\n    instance.move = move;\n    instance.undo = undo;\n    instance.getSteps = getSteps;\n    \n    return instance;\n\n})();\n\ngrid = Chess.grid;\ngetSteps = Chess.getSteps;","description":null,"note":null,"status":"public","like_student_ids":[],"is_featured":false,"views":63,"hashid":"gk4s4mj3","is_content_changed":false,"review_status":"unsubmitted","submitted_at":null,"reviewed_at":null,"advise":null,"is_deleted":false}

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