A.40,42,60,55,80,85B.42,45,55,60,85,80C.42,40,55,60,80,85D.42,40,60,85,55,80E.42,40,55,80,60,85
A.2n B.n C.n/2 D.n(n-1)
A.第i行非0元素的個(gè)數(shù)之和 B.第i列非0元素的個(gè)數(shù)之和 C.第i行0元素的個(gè)數(shù)之和 D.第i列0元素的個(gè)數(shù)之和