对角矩阵 当i-j>1时,a;=0,(1<=i,jn) a11a12 21a22a23 0 0 Anxn 0 a32a33a34 0 0 00 nn-1 a 维数组SA[1..3米n-2]作为数组A下三角元素的 存储结构 SA[k]=[a1,a1,a1,a22,a2,a32,a33,a34,,anm-1,an k=12345678 3n-33n2三对角矩阵 : 当|i-j| > 1时, aij = 0, (1<=i,j<=n) a11 a12 0 0 ... 0 a21 a22 a23 0 ... 0 Anxn = 0 a32 a33 a34 ... 0 ...... 0 0 0 ... ann-1 ann 一维数组SA[1..3*n-2]作为数组A下三角元素的 存储结构: SA[k]=[a11,a12,a21,a22,a23,a32,a33,a34,...,ann-1,ann] k = 1 2 3 4 5 6 7 8 3n-3 3n-2