Check validity of sudoku board

03.sudoku.cpp

// 03.sudoku.cpp
// juanfc 2018-02-06
//

#include <iostream>
#include <array>
using namespace std;

const int N = 9;
typedef array<int, N> TRow;
typedef array<TRow, N> TSudoku;

void checkSudoku(int n, TSudoku tab);
int countCell(TSudoku m, int cell, int n);
int countCol(TSudoku m, int col, int n);
int countRow(TSudoku m, int row, int n);

int main()
{
    TSudoku board1 = {{
            {{5, 3, 0, 0, 7, 0, 0, 0, 0}},
            {{6, 0, 0, 1, 9, 5, 0, 0, 0}},
            {{0, 9, 8, 0, 0, 0, 0, 6, 0}},
            {{8, 0, 0, 0, 6, 0, 0, 0, 3}},
            {{4, 0, 0, 8, 0, 3, 0, 0, 1}},
            {{7, 0, 0, 0, 2, 0, 0, 0, 6}},
            {{0, 6, 0, 0, 0, 0, 2, 8, 0}},
            {{0, 0, 0, 4, 1, 9, 0, 0, 5}},
            {{0, 0, 0, 0, 8, 0, 0, 7, 9}}
        }
    };
    TSudoku board2 = {{
            {{5, 3, 0, 0, 7, 0, 0, 0, 0}},
            {{6, 0, 0, 1, 9, 5, 0, 0, 0}},
            {{0, 9, 8, 0, 0, 0, 0, 6, 0}},
            {{8, 0, 3, 0, 6, 0, 0, 0, 3}},
            {{4, 0, 0, 8, 0, 3, 0, 0, 1}},
            {{7, 0, 0, 0, 2, 0, 0, 0, 6}},
            {{0, 6, 0, 0, 0, 0, 2, 8, 0}},
            {{0, 0, 0, 4, 1, 9, 0, 0, 5}},
            {{0, 0, 0, 0, 8, 0, 0, 7, 9}}
        }
    };
    TSudoku board3 = {{
            {{5, 3, 0, 0, 7, 0, 0, 0, 0}},
            {{6, 0, 0, 1, 9, 5, 0, 0, 0}},
            {{0, 9, 8, 0, 2, 0, 0, 6, 0}},
            {{8, 0, 0, 0, 6, 0, 0, 0, 3}},
            {{4, 0, 0, 8, 0, 3, 0, 0, 1}},
            {{7, 0, 0, 0, 2, 0, 0, 0, 6}},
            {{0, 6, 0, 0, 0, 0, 2, 8, 0}},
            {{0, 0, 0, 4, 1, 9, 0, 0, 5}},
            {{0, 0, 0, 0, 8, 0, 0, 7, 9}}
        }
    };
    TSudoku board4 = {{
            {{5, 3, 0, 0, 7, 0, 6, 0, 0}},
            {{6, 0, 0, 1, 9, 5, 0, 0, 0}},
            {{0, 9, 8, 0, 0, 0, 0, 6, 0}},
            {{8, 0, 0, 0, 6, 0, 0, 0, 3}},
            {{4, 0, 0, 8, 0, 3, 0, 0, 1}},
            {{7, 0, 0, 0, 2, 0, 0, 0, 6}},
            {{0, 6, 0, 0, 0, 0, 2, 8, 0}},
            {{0, 0, 0, 4, 1, 9, 0, 0, 5}},
            {{0, 0, 0, 0, 8, 0, 0, 7, 9}}
        }
    };
    checkSudoku(1, board1);
    checkSudoku(2, board2);
    checkSudoku(3, board3);
    checkSudoku(4, board4);
    return 0;
}


bool validSudoku(TSudoku m);
void printBoard(TSudoku m);

void checkSudoku(int n, TSudoku tab)
{
    // printBoard(tab);
    cout << "The board number " << n << " is a";
    if (validSudoku(tab)) // to solve!
        cout << " CORRECT Sudoku" << endl;
    else
        cout << "n INCORRECT Sudoku" << endl;
}

int countCol(TSudoku m, int col, int n);
int countRow(TSudoku m, int row, int n);
int countCell(TSudoku m, int cell, int n);

bool validSudoku(TSudoku m)
{
    bool isOk = true;

    int one2nine = 1;
    while (isOk and one2nine <= 9) {
        int col = 0;
        while (isOk and col < N) {
            isOk = (countCol(m, col, one2nine) <= 1);
            ++col;
        }
        ++one2nine;
    }

    one2nine = 1;
    while (isOk and one2nine <= 9) {
        int row = 0;
        while (isOk and row < N) {
            isOk = (countRow(m, row, one2nine) <= 1);
            ++row;
        }
        ++one2nine;
    }

    one2nine = 1;
    while (isOk and one2nine <= 9) {
        int cell = 0;
        while (isOk and cell < 9 ) {
            isOk = countCell(m, cell, one2nine) <= 1;
            ++cell;
        }
        ++one2nine;
    }

    return isOk;

}

int countCell(TSudoku m, int cell, int n)
{
    int cnt = 0;
    // There could be many ways to refer to cells
    // I've numbered cells from 0-8, going from the
    // top-left-> top-right to the bottom-right
    // The map is:
    // 0 -> 0,0   1 -> 0,3   2 -> 0,6
    // 3 -> 3,0   4 -> 3,3   5 -> 3,6
    // 6 -> 6,0   7 -> 6,3   8 -> 6,6
    int iorig = (cell / 3) * 3;
    int jorig = (cell % 3) * 3;
    for (int i = 0; i < 3; ++i)
        for (int j = 0; j < 3; ++j)
            if (m[iorig + i][jorig + j] == n)
                ++cnt;

    return cnt;
}
int countCol(TSudoku m, int col, int n)
{
    int cnt = 0;
    for (int row = 0; row < N; ++row)
        if (m[row][col] == n)
            ++cnt;
    return cnt;
}


int countRow(TSudoku m, int row, int n)
{
    int cnt = 0;
    for (int col = 0; col < N; ++col)
        if (m[row][col] == n)
            ++cnt;
    return cnt;
}
void printBoard(TSudoku m)
{
    for (int i = 0; i < N; ++i) {
        for (int j = 0; j < N; ++j)
            if (m[i][j] > 0)
                cout << m[i][j] << " ";
            else
                cout << "  ";
        cout << endl;
    }
}