Transitive Closure

% This function performs Transitive Closure on the input path matrix 'm',
% which is a directed acyclic graph (DAG),
% using simple matrix multiplication method.
% Example:
% input: m = [ 0 1 0;
% 0 0 1;
% 0 0 0];
% output: m = [ 0 1 1;
% 0 0 1;
% 0 0 0];