Sudoku solver

main.cpp

int field[9][9];

bool checkInRow(int number, int row)
{

    for (int i = 0; i < 9; i++)
    {
        if (field[row][i] == number)
            return true;
    }
    return false;

}

bool checkInCol(int number, int col)
{

    for (int i = 0; i < 9; i++)
    {
        if (field[i][col] == number)
            return true;
    }
    return false;

}
bool checkInBlock(int number, int blocknx, int blockny)
{

    for (int i = 0; i < 3; i++)
    {
        for (int j = 0; j < 3; j++)
        {
            if (field[i+blocknx][j+blockny] == number)
                return true;
        }
    }

    return false;
}

bool isAvalible(int x, int y, int number)
{
    return !checkInRow(number, x) && !checkInCol(number, y) && !checkInBlock(number, x - x%3 , y - y%3);
}

bool isZero(int x, int y)
{
    if (field[x][y] == 0)
        return true;
}

void generateField()
{
    for (int i = 0; i < 9; i++)
    {
        for (int j = 0; j < 9; j++)
        {
            field[i][j] = 0;
        }
    }
    int x, y, num;
    for (int i = 0; i < 25; i++)
    {
        x = rand()%9;
        y = rand()%9;
        num = (rand()%9)+1;
        if (isAvalible(x, y, num) && isZero(x, y))
        {
            field[x][y] = num;
        }
    }
}