#include <iostream>

#include <vector>

#include <ctime>

#include <cstdlib>

​

using namespace std;

​

// Function to print the Sudoku board

void printBoard(const vector<vector<int>>& board) {

    for (int i = 0; i < 9; i++) {

        for (int j = 0; j < 9; j++) {

            cout << board[i][j] << " ";

        }

        cout << endl;

    }

}

​

// Function to check if the user's solution is correct

bool isValidSolution(const vector<vector<int>>& board) {

    // Check all rows and columns

    for (int i = 0; i < 9; i++) {

        vector<bool> rowCheck(9, false);

        vector<bool> colCheck(9, false);

        for (int j = 0; j < 9; j++) {

            // Check the row

            if (board[i][j] != 0) {

                if (rowCheck[board[i][j] - 1]) return false;

                rowCheck[board[i][j] - 1] = true;

            }

            // Check the column

            if (board[j][i] != 0) {

                if (colCheck[board[j][i] - 1]) return false;

                colCheck[board[j][i] - 1] = true;

            }

        }

    }

​

    // Check all 3x3 subgrids

    for (int i = 0; i < 9; i += 3) {

        for (int j = 0; j < 9; j += 3) {

            vector<bool> gridCheck(9, false);

            for (int r = 0; r < 3; r++) {

                for (int c = 0; c < 3; c++) {

                    int val = board[i + r][j + c];

                    if (val != 0) {

                        if (gridCheck[val - 1]) return false;

                        gridCheck[val - 1] = true;

                    }

                }

            }

        }

    }

​

    return true;

}

​

// Function to generate a random Sudoku puzzle (simplified version)

void generateSudoku(vector<vector<int>>& board) {

    // Fill the board with an initial pattern (could be random)

    srand(time(0));

    for (int i = 0; i < 9; i++) {

        for (int j = 0; j < 9; j++) {

            // Randomly fill some cells (0 means empty)

            if (rand() % 4 == 0) {  // About 25% chance to leave a cell empty

                board[i][j] = 0;

            } else {

                board[i][j] = rand() % 9 + 1;  // Random number from 1 to 9

            }

        }

    }

}

​

// Function to allow the user to manually solve the puzzle

void getUserInput(vector<vector<int>>& board) {

    cout << "Enter your solution (fill 0 for empty cells):\n";

    int row, col, value;

    while (true) {

        printBoard(board);

        cout << "Enter row (1-9), column (1-9), and value (1-9), or -1 to submit: ";

        cin >> row;

        if (row == -1) break;  // Submit the solution

        cin >> col >> value;

        if (row >= 1 && row <= 9 && col >= 1 && col <= 9 && value >= 1 && value <= 9) {

            // Update the board

            board[row - 1][col - 1] = value;

        } else {

            cout << "Invalid input. Try again.\n";

        }

    }

}

​

// Main function

int main() {

    vector<vector<int>> board(9, vector<int>(9, 0));

    generateSudoku(board);

​

    cout << "Sudoku Puzzle: \n";

    printBoard(board);

​

    getUserInput(board);

​

    cout << "\nYour solution: \n";

    printBoard(board);

​

    if (isValidSolution(board)) {

        cout << "Congratulations! Your solution is correct.\n";

    } else {

        cout << "Sorry, your solution is incorrect. Try again.\n";

    }

​

    return 0;

}

​

OFFSET -- specifies the number of rows to skip before selecting

-- In MySQL OFFSET keyword cannot be used alone without the LIMIT keyword.

"MySQL"

select * from Employee  LIMIT 1 OFFSET 3;

-- selects 1 row after skipping 3 rows

​

-- In SQL Server, the OFFSET keyword cannot be used without an ORDER BY clause

"SQL Server"

select * from Employee order by Salary offset 1 rows

-- selects rows after skipping 1 row ordered by Salary column in ascending order