% queen attacks test
% This program finds the number of attacks between the queens
% on the board. Queens are represented by 1s, empty places are represented by 0s.
% The board size is N.

clear
clc
N=5;
% A = ones(N);
A=rand(N)>0.5;
% A = [1 1 0 1 1; 0 1 0 1 0; 1 1 0 0 1; 0 1 1 1 0; 0 0 1 1 1];
num_attacks = 0;

% count horizontal attacks
for i = 1 : N
  temp = sum(A(i, :));
  if (temp < 2)
    temp2 = 0;
  else
    temp2 = cumsum(1 : temp - 1);
    temp2 = temp2(end);
  end
  num_attacks = num_attacks + temp2;
end

% count vertical attacks
for i = 1 : N
  temp = sum(A(:, i));
  if (temp < 2)
    temp2 = 0;
  else
    temp2 = cumsum(1 : temp - 1);
    temp2 = temp2(end);
  end
  num_attacks = num_attacks + temp2;
end

% count diagonal attacks
for i = -(N-2) : (N-2)
  temp = sum(diag(A, i));
  if (temp < 2)
    temp2 = 0;
  else
    temp2 = cumsum(1 : temp - 1);
    temp2 = temp2(end);
  end
  num_attacks = num_attacks + temp2;
end

% count antidiagonal attacks
A = fliplr(A);
for i = -(N-2) : N-2
  temp = sum(diag(A, i));
  if (temp < 2)
    temp2 = 0;
  else
    temp2 = cumsum(1 : temp - 1);
    temp2 = temp2(end);
  end
  num_attacks = num_attacks + temp2;
end