How to find the common elements of 2 cell arrays that contain randperm elements?

问题

I have two cell arrays which may not be of the same size. Elements of cell arrays is randperm of an integer number. randperm data Type is double array. How can I find common elements of two cell arrays?

For example:

Q1 = {[1 2 3 4], [3 2 4 1], [4 2 1 3]}
Q2 = {[2 4 3 1], [1 2 3 4], [1 2 4 3]} 

As I said elements of cell arrays are randperm. I want the output of above example be "Element-1 of Q1 i.e. [1 2 3 4] since it is also present in Q2. Note: Cell Arrays may have different number of columns...

回答1:

Vertically concatenate the matrices inside the cell arrays and use intersect with the 'rows' flag. i.e.

Q1={[1 2 3 4], [3 2 4 1], [4 2 1 3]}; 
Q2={[2 4 3 1], [1 2 3 4], [1 2 4 3]};
Qout = intersect(vertcat(Q1{:}), vertcat(Q2{:}), 'rows');

%>> Qout
%Qout =
%     1     2     3     4

回答2:

You can do it by using two loops and check all off them.

q1=[1 2 3 4; 3 2 4 1; 4 2 1 3];
q2=[2 4 3 1; 1 2 3 4; 1 2 4 3];

%find the size of matrix
[m1,n1] = size(q1);
[m2] = size(q2,1);

for (ii=1:m1)
    for (jj=1:m2)
        %if segments are equal, it will return 1
        %if sum of same segment = 4 it means they are same
        if ( sum( q1(ii,:) == q2(jj,:) ) == n1)
            ii %result of q1
            jj %result of q2
            break;
        end
    end
end

来源：https://stackoverflow.com/questions/44913957/how-to-find-the-common-elements-of-2-cell-arrays-that-contain-randperm-elements