又一道。。。。。。how to prove that a tree with v vertices has v-1 edges?[为什么这样子？ (9-9 0:59, Long long ago)] [ 传统版 | sForum ][登录后回复]1楼

找本图论的书看一下吧！肯定有的。[南岳之麓 (9-9 9:39, Long long ago)] [ 传统版 | sForum ][登录后回复]2楼

inductionif v=1, then e=0. ture.

assume the statement is true for v<=k, (k>=1).
for v=k+1, we can always find a leaf, remove it, and the edge it connect to. then v-1 verteices and e-1 edges left. from assumption, (e-1)=(v-1)-1, or e=v-1.[zzjbug (9-10 0:56, Long long ago)] [ 传统版 | sForum ][登录后回复]3楼