let board = [
    ["5", "3", ".", ".", "7", ".", ".", ".", "."],
    ["6", ".", ".", "1", "9", "5", ".", ".", "."],
    [".", "9", "8", ".", ".", ".", ".", "6", "."],
    ["8", ".", ".", ".", "6", ".", ".", ".", "3"],
    ["4", ".", ".", "8", ".", "3", ".", ".", "1"],
    ["7", ".", ".", ".", "2", ".", ".", ".", "6"],
    [".", "6", ".", ".", ".", ".", "2", "8", "."],
    [".", ".", ".", "4", "1", "9", ".", ".", "5"],
    [".", ".", ".", ".", "8", ".", ".", "7", "9"],
];

function isValidRow(board, row) {
    let seen = new Set();
    for (let i = 0; i < 9; i++) {
        let num = board[row][i];
        if (num !== 0 && seen.has(num)) {
            return false;
        }
        seen.add(num);
    }
    return true;
}

function isValidColumn(board, col) {
    let seen = new Set();
    for (let i = 0; i < 9; i++) {
        let num = board[i][col];
        if (num !== 0 && seen.has(num)) {
            return false;
        }
        seen.add(num);
    }
    return true;
}

function isValidSubgrid(board, startRow, startCol) {
    let seen = new Set();
    for (let row = startRow; row < startRow + 3; row++) {
        for (let col = startCol; col < startCol + 3; col++) {
            let num = board[row][col];
            if (num !== 0 && seen.has(num)) {
                return false;
            }
            seen.add(num);
        }
    }
    return true;
}

function isValidSudoku(board) {
    result: HTMLElement = document.getElementById("result");

    for (let i = 0; i < 9; i++) {
        if (!isValidRow(board, i) || !isValidColumn(board, i)) {
            console.log("Board is Unvalid");
            result.innerHTML = "Result: Unvalid";
            return false;
        }
    }
    for (let i = 0; i < 9; i += 3) {
        for (let j = 0; j < 9; j += 3) {
            if (!isValidSubgrid(board, i, j)) {
                console.log("Board is Unvalid");
                result.innerHTML = "Result: Unvalid";
                return false;
            }
        }
    }
    console.log("Board is Valid");
    result.innerHTML = "Result: Valid";
    return true;
}