Walks, paths and circuits
Graph theory · Mathematics
Study notes
Q: In square ABCD with diagonal AC, classify: (a) A-B-C-A, (b) A-B-C-A-C. (a) A-B-C-A: vertices A,B,C distinct, returns to A - a CYCLE (closed path)! (b) A-B-C-A-C: vertex A repeats mid-way, and the diagonal edge AC is traversed twice - so it is only a WALK (not even a trail, since trails need distinct edges).