秦 算法2.2改进的平方根法 1:forj=1 ton do%先计算分解 2 4,=a-∑d4 3: for i=j+1 to n do 4: l6=(a-∑1 likdkljk)/d 5: end for 6:end for 7:=b1 %解方程组：Ly=b和DLTx=y 8:for i=2 to n do 9:： =b:-∑1lk张 10:end for 11:In =yn/dn 12:for i=n-1 to 1 do 13: xi=/d-∑k=i+1lktk 14:end for http://math.ecnu.edu.cn/~jypan 9/42 算法 2.2 改进的平方根法 1: for j = 1 to n do % 先计算分解 2: dj = ajj − ∑ j − 1 k=1 l 2 jk d k 3: for i = j + 1 to n do 4: lij = ( aij − ∑ j − 1 k=1 lik d k ljk)/ dj 5: end for 6: end for 7: y 1 = b 1 % 解方程组 : Ly = b 和 DL ⊺ x = y 8: for i = 2 to n do 9: y i = b i − ∑ i − 1 k=1 lik y k 10: end for 11: x n = y n / d n 12: for i = n − 1 to 1 do 13: x i = y i / d i − ∑ nk = i+1 lki x k 14: end for http://math.ecnu.edu.cn/~jypan 9/42