(A,E)=
1 1 1 ...1 1 1 0 0 ...0 0
0 1 1 ...1 1 0 1 0 ...0 0
0 0 1 ...1 1 0 0 1 ...0 0
............
0 0 0 ...1 1 0 0 0 ...1 0
0 0 0 ...0 1 0 0 0 ...0 1
ri - r(i+1),i=1,2,...,n-1 --依次上一行减下一行
1 0 0 ...0 0 1 -1 0 ...0 0
0 1 0 ...0 0 0 1 -1 ...0 0
0 0 1 ...0 0 0 0 1 ...0 0
............
0 0 0 ...1 0 0 0 0 ...1 -1
0 0 0 ...0 1 0 0 0 ...0 1
所以 A^-1=
1 -1 0 ...0 0
0 1 -1 ...0 0
0 0 1 ...0 0
......
0 0 0 ...1 -1
0 0 0 ...0 1