I had this question today when I wrote breadth first search,
Solutions:
I’m being silly, obviously an array, I wrote mate(I, j), and then I changed it to mate[I, j];

Oh, I’m a fool again
“Mate [I][j]” is ok

I’m being silly, obviously an array, I wrote mate(I, j), and then I changed it to mate[I, j];

Oh, I’m a fool again
“Mate [I][j]” is ok