摘要： In this paper,we solve a problem proposed by Guo zhong about the uniqueness of n×n primitive matrices with the smallest number of positi- ve entries which have n positive diagonal entries and primitive exponent k.
We also prove that the exponent set E(n,d)of the class of n×n primiti- ve matrices with d(1≤d≤n-1)positive diagonal entries is E(n,d)={2, 3,…,2n-d-1}.
