数据结构ArrandMatr幻灯片.ppt

4.5 Sparse Matrices ** void Transpose(SparseMatrixT b)const; void Add(const SparseMatrixTb, SparseMatrixT c)const; private: void Append(const TermTt); int rows,cols; //matrix dimensions int terms ; //current number of nonzero terms TermT*a; //term array int MaxTerms; //size of array a } 4.5 Sparse Matrices ** 1).SparseMatrix constructor Template class T SparseMatrixT::SparseMatrix(int maxTerms) { if(maxTerms1)throw BadInitializers(); MaxTerms=maxTerms; a=new TermT[MaxTerms]; terms=rows=cols=0; } 4.5 Sparse Matrices ** 2)SparseMatrix input and output codes overload templateclass T ostream operator(ostream out, const SparseMatrixTx) {//put *this in output stream. 4.5 Sparse Matrices ** out“rows=“x.rows“columns=“x.colsendl; out“nonzero terms=“x.termsendl; for(int i=0;ix.terms;i++) out“a(“x.a[i].row’,’x.a[i].col“)=“ x.a[i].valueendl; return out; } 4.5 Sparse Matrices ** overload templateclass T istream operator(istream in, SparseMatrixT x) { //input a sparse matrix cout“Enter number of rows,columns,and terms” endl; inx.rowsx.colsx.terms; if(x.termsx.MaxTerms)throw NoMem(); 4.5 Sparse Matrices ** for(int i=0;ix.terms;i++) { cout“Enter row,column, and value of term” (i+1)endl; inx.a[i].rowx.a[i].colx.a[i].value; } return in; } 4.5 Sparse Matrices ** 0 0 0 2 0 0 0 6 0 0 7 0 0 0 0 9 0 0 0 4 5 0 0 0 3) Transposing a Sparse Matrix For example 0 0 0 0 0 6 0 4 0 0 0 5 2 0 9 0 0 7 0 0 0 0 0 0 Before transpose after transpose 4.5 Sparse Matrices ** 1 4 2 2 2 6 2 5 7 3 4 9 4 2 4 4 3 5 row col value 2 2 6 2 4