1. Advanced Data Structure using C++

LECTURE NOTES OF ADVANCED DATA STRUCTURE (MT-CSE 110)
JA = (1, 4, 7, 10, 12, 12, 14)
5. Storage‐by‐Rows
The storage mode used for sparse matrices stored by rows has
three variations, depending on whether the matrix is a general
sparse matrix or a symmetric sparse matrix. This explains these
variations.
For a general sparse matrix A, storage‐by‐rows uses three one‐
dimensional arrays to define the sparse matrix storage, AR, IA, and
JA. Given the m by n sparse matrix A having ne nonzero elements,
the arrays are set up as follows:
• AR of (at least) length ne contains the ne nonzero elements of
the sparse matrix A, stored contiguously. The rows of matrix
A are stored consecutively from 1 to m in AR. The elements in
each row of A are stored in any order in AR.
• IA, an integer array of (at least) length m+1 contains the
relative starting position of each row of matrix A in array AR;
that is, each element IA(i) of the row pointer array indicates
where row i begins in array AR. If all elements in row i are
zero, then IA(i) = IA(i+1). The last element, IA(m+1), indicates
the position after the last element in array AR, which is ne+1.
• JA, an integer array of (at least) length ne contains the
corresponding column numbers of each nonzero element, aij,
in matrix A.
Consider the following as an example of a 6 by 6 general sparse
matrix A and how it can be stored in arrays AR, IA, and JA.
Given the following matrix A:
Prepared By :­
Er. Harvinder Singh
Assist Prof., CSE, H.C.T.M (Kaithal) Page ‐ 132 ‐