#include <fstream>

#include <vector>

#include <iostream>

#include <string>

using namespace std;

bool check_sudoku(const vector<int>& input);

int coordtoidx(int row, int col);

void extract_row(const vector<int>& input, int row, vector<int>& output);

void extract_col(const vector<int>& input, int col, vector<int>& output);

void extract_subsquare(const vector<int>& input, int row, int col, vector<int>& output);

bool once(int num,const vector<int>& input);

int main()

{

    ifstream infile;

    cout<<"Please input a input file name"<<endl;

    string infilename;

    cin>>infilename;

    infile.open(infilename);

    if (!infile.is_open())

    {

        cout<<"could not open input file"<<endl;

        system("pause");

        exit(EXIT_FAILURE);

    }

    vector<int> input;

    int number;

    while (infile>>number)

    {

        input.push_back(number);

    }

    infile.close();

    bool isOK=check_sudoku(input);

    if (isOK)

    {

        cout<<"valid"<<endl;

    }

    else

    {

        cout<<"invalid"<<endl;

    }

    system("pause");

    return ;

}

bool check_sudoku(const vector<int>& input)

{

    for (int i=; i<; i++)

    {

        vector<int> rowNumbers;

        extract_row(input,i,rowNumbers);

        for (int m=;m<;m++)

        {

            bool onceFlag=once(m,rowNumbers);

            if(!onceFlag)

            {

                return false;

            }

        }

    }

    for (int j=; j<; j++)

    {

        vector<int> colNumbers;

        extract_col(input,j,colNumbers);

        for (int m=;m<;m++)

        {

            bool onceFlag=once(m,colNumbers);

            if(!onceFlag)

            {

                return false;

            }

        }

    }

    for (int p=; p<; p=p+)

        for (int q=; q<; q=q+)

    {

        vector<int> subsquareNumbers;

        extract_subsquare(input,p,q,subsquareNumbers);

        for (int m=;m<;m++)

        {

            bool onceFlag=once(m,subsquareNumbers);

            if(!onceFlag)

            {

                return false;

            }

        }

    }

    return true;

}

int coordtoidx(int row, int col)

{

    return row*+col;

}

void extract_row(const vector<int>& input, int row, vector<int>& output)

{

    for (int c=; c<;c++)

    {

        int idx=coordtoidx(row,c);

        output.push_back(input.at(idx));

    }

}

void extract_col(const vector<int>& input, int col, vector<int>& output)

{

    for (int r=; r<;r++)

    {

        int idx=coordtoidx(r,col);

        output.push_back(input.at(idx));

    }

}

void extract_subsquare(const vector<int>& input, int row, int col, vector<int>& output)

{

    for (int r=row; r<row+;r++)

        for (int c=col; c<col+;c++)

    {

        int idx=coordtoidx(r,c);

        output.push_back(input.at(idx));

    }

}

bool once(int num, const vector<int>& input)

{

    int count=;

    for (unsigned int i=; i<input.size(); i++)

    {

        if (input.at(i)==num)

        {

            count++;

        }

    }

    return count==?true:false;

}