C + + implementation of sparse matrix compression storage, transpose, fast transpose

/* Compression storage, transpose, quick transpose for sparse matrix */#include  <iostream>using namespace std; #include  <vector>/ /Ternary Group template<class t>struct triple{size_t _row;size_t _col; t _value; Triple (Size_t row = 0, size_t col = 0, const t& value  = t ()): _row (Row), _col (col), _value (value) {}};template<class t>class sparsematrix{ Public:sparsematrix (t* a = null, size_t m = 0, size_t n =  0, const t& invalid = t ()): _rowsize (M), _colsize (N), _invalid (invalid) {for   (size_t i = 0; i < m; ++i) {for  (size_t j = 0; &NBSP;J&NBSP;&LT;&NBSP;N;&NBSP;++J) {if  (a[i*n+j] != _invalid) {Triple<t> t;t._row  = i;t._col = j;t._value = a[i*n+j];_a.push_back (t);}}} Void display () {size_t index = 0;for  (Size_t i = 0; i < _rowsize; ++i) {for  (size_t j = 0; &NBSP;J&NBSP;&LT;&NBSP;_COLSIZE;&NBSP;++J) {if  (Index < _a.size () &&  (_a[index]._ Row == i) &&  (_a[index]._col == j)) {cout<<_a[index++]._value<< "   ";} else{cout<<_invalid<< " ";}} Cout<<endl;}} Matrix transpose   Time complexity is  o (number of valid data * Number of columns of the original matrix) Sparsematrix<t> transport () {sparsematrix<t> sm; sm._colsize = _rowsize;sm._rowsize = _colsize;sm._invalid = _invalid;for  ( Size_t i = 0; i < _colsize; ++i) {Size_t index = 0;while   (Index < _a.size ()) {if  (_a[index]._col == i) {Triple<t> t;t._row  = _a[index]._col;t._col = _a[index]._row;t._value = _a[index]._value;sm._a.push _back (t);} ++index;}} RETURN&NBSP;SM;} Quick transpose   time complexity O (withNumber of valid data + number of columns of the original matrix) Sparsematrix<t> fasttransport () {sparsematrix<t> sm;sm._rowsize =  _colsize;sm._colsize = _rowsize;sm._invalid = _invalid;int* rowcounts =  new int[_colsize];int* rowstart = new int [_colsize];memset (RowCounts,  0, sizeof (int) *_colsize); memset (rowstart, 0, sizeof (int) *_colsize); Size_t index  = 0;while  (Index < _a.size ()) {++rowcounts[_a[index]._col];++index;} for  (size_t i = 1; i < _colsize; ++i) {RowStart[i] =  ROWSTART[I-1]&NBSP;+&NBSP;ROWCOUNTS[I-1];} Index = 0;sm._a.resize (_a.size ());while  (Index < sm._a.size ()) {Triple<T>  t;t._row = _a[index]._col;t._col = _a[index]._row;t._value = _a[index]._ Value;sm._a[rowstart[_a[index]._col]] = t;++rowstart[_a[index]._col];++index;} Delete[] rowcounts;delete[]&NBSP;ROWSTART;RETURN&NBSP;SM;} protected:vector<triple<t>> _a;size_t _rowsize;size_t _colsize; t _invalid;}; Void test () {int array [6][5] = {{1, 0, 3, 0, 5},{0, 0,  0, 0, 0},{0, 0, 0, 0, 0},{2, 0, 4, 0, 6},{0, 0, 0,  0, 0},{0, 0, 0, 0, 0}}; SPARSEMATRIX&LT;INT&GT;&NBSP;SM1 ((int*) array, 6, 5, 0); Sm1. Display (); cout<<endl;//sprsematrix<int> sm2 = sm1. Transport (); Sparsematrix<int> sm2 = sm1. Fasttransport (); sm2. Display ();} Int main () {Test (); return 0;}

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C + + implementation of sparse matrix compression storage, transpose, fast transpose