#include <iostream>
#include <cstdlib>
#include <vector>
#include <sstream>
#include <climits>

using namespace std;

int testUnique(vector<int>);
void bubbleSort(vector<int>&);
int checkMagic(int, int);

int main()
{
    int i, j, length, tmp, n;
    char buff[1000];
    stringstream s (ios_base::in);

    cout << "N?" << endl;

// Gets the side length of the square from the user
// and makes sure only one whole number greater than
// zero was entered

    cin.get(buff,1000);

    s.clear();
    s.str(buff);

    length = 0;
        while(!s.eof() ) {
            s >> n;
            ++length;

            if (s.fail()) {
                s.clear();
                s.ignore();
                continue;
            }
        }

    if (length != 1 || n%1 != 0 || n<1) {
        cerr << "Non-valid dimension." << endl;
        exit(EXIT_FAILURE);
    }

// Reads in the numbers of the matrix row-wise

    cout << "Enter your numbers:" << endl;

    cin.clear();
    cin.ignore();

    cin.get(buff, 1000);

    s.clear();
    s.str(buff);

    vector<int> nums(n*n);

    i = 0;
    while(!s.eof() ) {
        s >> nums[i];
        ++i;

        if (s.fail()) {
                s.clear();
                s.ignore();
                continue;
            }
    }

// Test for n^2 numbers:

    if (i != n*n) {
        cerr << "Not enough elements!" << endl;
        exit(EXIT_FAILURE);
    }

    if (testUnique(nums) != 0) {
        cerr << "All elements not unique!" << endl;
        exit(EXIT_FAILURE);
    }

    bubbleSort(nums);

//  To check all values between 1 and n

    while (true) {

        if (nums[0] != 1 || nums[n*n-1] != n*n) {
            cerr << "Not all numbers 1 to n!" << endl;
            exit(EXIT_FAILURE);
        }

        for (i= (n*n)-1; i>0; i--) {
            if (nums[i] - nums[i-1] != 1) {
                cerr << "Not all numbers 1 to n!" << endl;
                exit(EXIT_FAILURE);
            }
        }
        break;
    }

// Convert to matrix:

    int magic[n][n];
    int k = 0;

    for (i=0; i<n; i++) {
        for (j=0; j<n; j++) {

            magic[i][j] = nums[k];
            k++;
        }
    }

    cout << "You entered the " << n << " by " << n << " matrix: " << endl << endl;

        for (i=0; i<n; i++) {
            for (j=0; j<n; j++) {

                cout << magic[i][j] << " ";
            }
            cout << endl;
        }


    cout << endl;

    cout << checkMagic(magic, n);

    return 0;
}

int testUnique(vector<int> v)
{
    int i, j, n;
    n = v.size();

    for (i=0; i<n-1; i++) {
        for (j=i+1; j<n; j++) {

            if (v[i] == v[j])
            return -1;
        }
    }
    return 0;
}

void bubbleSort(vector<int> &v)
{
    int i, j, n, tmp;
    n = v.size();

    for (i=0; i<n; i++) {
        for (j=0; j<i; j++) {

            if (v[i] < v[j]) {
                tmp = v[i];
                v[i] = v[j];
                v[j] = tmp;
            }
        }
    }
}

int checkMagic(int magic[][n], int a)
{
    int i, j, sum, test;
    sum = test = 0;

// Get initial value to check all sums against
    for (i=0; i<a; i++)
        test += magic[i][1];

// Test rows against "test"
    for (i=1; i<a; i++) {
        for (j=0; j<a; j++)
            sum += magic[i][j];

            if (sum != test)
                return 1;
        }

        sum = 0;
    }

// Test columns against "test"
    for (i=0; i<a; i++) {
        for (j=0; j<a; j++)
            sum += magic[j][i];

            if (sum != test)
                return 1;
        }

        sum = 0;
    }

// Test diagonals
    for (i=0; i<a; i++) {
        for(j=i; j<a; j++) {
            sum += magic[j][i];

            if (sum != test)
                return 1;
        }

        sum = 0;
    }
    return 0;
}