def queens_collide?(i, j, col, diag_plus, diag_minus) col.include?(j) diag_plus.include?(i + j) diag_minus.include?(i - j) end def place_queens(n, i, j, col, diag_plus, diag_minus) if i.zero? col elsif j.zero? false elsif queens_collide?(i, j, col, diag_plus, diag_minus) place_queens(n, i, j - 1, col, diag_plus, diag_minus) else queen_placed_ok = place_queens( n, i - 1, n, col + [j], diag_plus + [i + j], diag_minus + [i - j] ) if queen_placed_ok queen_placed_ok else place_queens(n, i, j - 1, col, diag_plus, diag_minus) end end end def queens(n) place_queens(n, n, n, [], [], []) end puts queens(4).inspect # >> [3, 1, 4, 2]

#include<stdio.h>

unsigned sum_row (unsigned* sq, const unsigned width, const unsigned row) {

unsigned sum, col;

sum = 0;

for (col=0; col<width; ++col)

sum += sq[row*width+col];

return sum;

}

unsigned sum_col (unsigned* sq, const unsigned width, const unsigned col) {

unsigned sum, row;

sum = 0;

for (row=0; row<width; ++row)

sum += sq[row*width+col];

return sum;

}

unsigned sum_diag (unsigned* sq, const unsigned width) {

unsigned sum, row, col;

sum = 0;

for (row=0, col=0; row<width; ++row, ++col)

sum += sq[row*width+col];

return sum;

}

unsigned sum_anti (unsigned* sq, const unsigned width) {

unsigned sum, row, col;

sum = 0;

for (row=0, col=width-1; row<width; ++row, --col)

sum += sq[row*width+col];

return sum;

}

bool is_magic (unsigned* sq, const unsigned width) {

unsigned magic, row, col;

magic = sum_row (sq, width, 0);

for (row=1; row<width; ++row)

if (magic!=sum_row(sq, width, row))

return false;

for (col=0; col<width; ++col)

if (magic!=sum_col(sq, width, col))

return false;

if (magic!=sum_diag(sq, width))

return false;

if (magic!=sum_anti(sq, width))

return false;

return true;

}

int main () {

const unsigned width = 3;

unsigned a[width][width] {{2,7,6},{9,5,1},{4,3,8}};

unsigned row, col;

printf ("Square:\n\n");

for (row=0; row<width; ++row) {

for (col=0; col<width; ++col) {

printf ("%d ", a[row][col]);

}

printf ("\n");

}

printf ("\n");

if (is_magic((unsigned*)&a, width))

printf ("The square is magic with a magic constant of %d\n", sum_row((unsigned*)&a, 3,0));

else

printf ("The square is not magic\n");

return 0;

}

To Find the number in that matrix and check that number adjacency elements...

import java.util.Scanner;

public class FindAdjacencyMatrix {

public static int[][] array1 = new int[30][30];

public static int i,j,num,m,n;

public static void main(String args[]) {

Scanner input = new Scanner(System.in);

//-------------------------------------------------------------------------------------------------

System.out.println("Enter the m ,n matrix");

m = input.nextInt();

n = input.nextInt();

//-------------------------------------------------------------------------------------------------

System.out.println("Enter the matrix Element one by one:");

for(i = 0; i < m; i++) {

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

array1[i][j] = input.nextInt();

}

}

System.out.println("The Given Matrix is :");

for(i = 0; i < m; i++) {

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

System.out.print(" "+array1[i][j]);

}

System.out.print("\n");

}

//-------------------------------------------------------------------------------------------------

System.out.println("Find The Adjacency Elements for Given Number : ");

System.out.println("Enter The Number : ");

num = input.nextInt();

for(i = 0; i < m; i++) {

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

if(num == array1[i][j]) {

System.out.println("Element is Found :"+num);

findAdjacency(num,i,j);

break;

}

}

}

//--------------------------------------------------------------------------------------

}

private static void findAdjacency(int elem,int row,int col) {

try {

if( array1[row][col-1]!=-1) {

System.out.println("Left Adjacency : "+array1[row][col-1]);

}

} catch(Exception e){

System.out.println(" Exception Throwing ");

}

try{

if(array1[row][col+1]!= -1) {

System.out.println("Right Adjacency : "+array1[row][col+1]);

}

}catch(Exception e){

System.out.println(" Exception Throwing ");

}

try {

if(array1[row-1][col]!= -1) {

System.out.println("Top Adjacency : "+array1[row-1][col]);

}

} catch(Exception e){

System.out.println(" Exception Throwing ");

}

try {

if(array1[row+1][col]!= -1) {

System.out.println("Botto Adjacency : "+array1[row+1][col]);

}

} catch(Exception e){

System.out.println(" Exception Throwing ");

}

}

//----------------------------------------------------------------------------------------------

}

Anthony Del Col is 6' 1".