Necessary and sufficient conditions are given for the finiteness of the generalized exponents expD(k), f(D, k) and F(D, k) for digraphs which are not necessarily primitive. Also the largest finite value of the general...Necessary and sufficient conditions are given for the finiteness of the generalized exponents expD(k), f(D, k) and F(D, k) for digraphs which are not necessarily primitive. Also the largest finite value of the generalized exponent expD(k) for digraphs of order n is determined and the complete characterizations of the extreme digraphs are given.展开更多
文摘Necessary and sufficient conditions are given for the finiteness of the generalized exponents expD(k), f(D, k) and F(D, k) for digraphs which are not necessarily primitive. Also the largest finite value of the generalized exponent expD(k) for digraphs of order n is determined and the complete characterizations of the extreme digraphs are given.