Javascript 如何在Connect 4游戏中 for each 玩家使用位板寻找7形状

class Connect4 {
    static {
        // Two static variables:
        this.cellToGroups = Array.from({length: 7*7}, () => []);
        this.groupToCells = [];
        
        const register = (row, col, shift) => {
            let cellId = row + col * 7;
            const group = [];
            // Collect the four cells that make up the group
            // And for each cell add a the id of the group it is in
            for (let i = 0; i < 4; i++) {
                group.push(cellId);
                this.cellToGroups[cellId].push(this.groupToCells.length);
                cellId += shift;
            }
            this.groupToCells.push(group);
        };
        // All vertical groups
        for (let row = 0; row < 3; row++) {
            for (let col = 0; col < 7; col++) {
                register(row, col, 1);
            }
        }
        // All horizontal groups
        for (let row = 0; row < 7; row++) {
            for (let col = 0; col < 4; col++) {
                register(row, col, 7);
            }
        }
        // All diagonal groups
        for (let row = 0; row < 3; row++) {
            for (let col = 0; col < 4; col++) {
                register(row, col, 8);
                register(5 - row, col, 6);
            }
        }
    }
    constructor() {
        this.bitboard = [0n, 0n];
        this.heights = [0, 0, 0, 0, 0, 0, 0];
        // For each group: array with cells taken by X, taken by O, taken by neither
        this.groupOccupation = Connect4.groupToCells.map(cells => [[], [], [...cells]]); 
        this.threats = [0n, 0n]; // Same structure as bitboard: a 1 indicates a winning move (if reachable)
        this.moves = []; // History of played moves (columns)
    }
    move(col) {
        const row = this.heights[col];
        if (row == 6) throw "Invalid move";
        const player = this.moves.length % 2;
        const cellId = row + col * 7;
        const bit = 1n << BigInt(cellId);
        this.heights[col]++;
        this.bitboard[player] |= bit;
        // Incrementally update the occupation this player has in the groups
        //    that this cell is part of
        for (const groupId of Connect4.cellToGroups[cellId]) {
            const group = this.groupOccupation[groupId];
            // In this group, mark the cell as taken by this player
            let i = group[2].indexOf(cellId);
            group[player].push(...group[2].splice(i, 1));
            // Check if this group is completed or becomes a threat
            if (group[player].length === 4) this.gameOver = true;
            if (group[player].length === 3 && group[2].length) { // Making a threat!
                this.threats[player] |= 1n << BigInt(group[2][0]);
            }
        }
        this.moves.push(col);
    }
    toString() {
        return Array.from({length: 6}, (_, top) =>
            Array.from({length: 7}, (_, col) => {
                const bit = BigInt(5 - top + col * 7);
                return (this.bitboard[0] >> bit) & 1n ? "X" 
                     : (this.bitboard[1] >> bit) & 1n ? "O" 
                     // Output the threats with small letters
                     : (this.threats[0] >> bit) & 1n ? "x"
                     : (this.threats[1] >> bit) & 1n ? "o"
                     : ".";
            }).join(" ")
        ).join("\n");
    }
}

// Demo
const game = new Connect4();
const moves = [3, 3, 3, 3, 3, 0, 1, 1, 0, 4, 0, 4];
for (const move of moves) game.move(move);
console.log("" +game);