Transpose and quick transpose of C + + matrices

Transpose of the Matrix

Swap the rows and columns of the original matrix, that is, the data on [I][j] and [j][i] positions.

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Program code:

#include <vector>   //sparse matrix push pop operator[]  and sequential table consistent  template<class  t>struct triple  //defines a ternary group   can be accessed directly as defined as struct{size_t _row;size_t _col; T _value; triple (Size_t row, size_t col, const t& value): _row (Row) ,  _col (COL),  _value (value) {}};  template<class t>class sparsematrix{public : Sparsematrix (Size_t m, size_t n, const t&invalid): _M (M),  _N (N),  Invalid (invalid) { }sparsematrix (const t* a, size_t m, size_t n,const t & invalid)//const t& invalid indicates which is invalid data: _m (M),  _n (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)  //not equal to invalid value {Triple <t> t (I, j,&NBSP;A[I*N&NBSP;+&NBSP;J]); _a.push_back (t);    }}}} void display () {Size_t index  = 0;for  (size_t i = 0; i < _m; ++i) {for  (size_t &NBSP;J&NBSP;=&NBSP;0;&NBSP;J&NBSP;&LT;&NBSP;_N;&NBSP;++J) {if  (index<_a.size () &&i ==  _a[index]._row && j == _a[index]._col) {Cout << _a[index]. value <<  " "; ++index;} else{cout << _invalid <<  " ";}} Cout << endl;} Cout << endl;}  sparsematrix<t> transport ()       //transpose {      //time Complexity  o (number of valid data *n (column)) SPARSEMATRIX&LT;T&GT;&NBSP;SM (_n,_m,_invalid); for  (size_t i  = 0; i < n; ++i) {size_t index = 0;while  (index <  _a.size ()) {if  (_a[index].col == i) {TRIPLE&LT;T&GT;&NBSp;t (_a[index]._col, _a[index]._row, _a[index]._value); Sm._a.push_back (t);} ++index;}} RETURN&NBSP;SM;} protected:        //Storage Ternary Array//triple<t>* _a;         Direct use of dynamic sequential table vector<triple<t>> _a;size_t _m;size_t _n; t _invalid;};  void test2 () {int a[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;SM ((int*) a,6,5,0)  //cast to a one-dimensional array   array  6 row  5 column   illegal value 0SM. Display ();  sparsematrix<int> sm2 = sm. Transport (); sm2. Display ();}   #include <iostream>using namespace std;  #include <stdlib.h> #include "Matrix.h"  int main () {//test1 (); Test2 (); System ("pause"); return 0;}

Operation Result:

1 0 0 2 0 0

0 0 0 0 0 0

3 0 0 4 0 0

0 0 0 0 0 0

5 0 0 6 0 0

Quick Transpose

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Program code:

#include <vector>   //sparse matrix push pop operator[]  and sequential table consistent  template<class  t>struct triple  //defines a ternary group   can be accessed directly as defined as struct{size_t _row;size_t _col; T _value; triple (Size_t row=0, size_t col=0, const t& value=t ())// Const temporary object has constancy: _row (Row),  _col (col),  _value (value) {}};  template<class t>class  sparsematrix{public:sparsematrix (size_t m, size_t n, const t&invalid): _M (M) ,  _n (N),  invalid (invalid) { }sparsematrix (const t* a, size_t m, size_t  n,const t& invalid)//const t& invalid indicates which is invalid data: _m (M),  _n (N),  Invalid (invalid) {for  (size_t i = 0; i < m; ++i) {for  (size_t &NBSP;J&NBSP;=&NBSP;0;&NBSP;J&NBSP;&LT;&NBSP;N;&NBSP;++J) {if  (a[i*n + j] != invalid)  //not equal to invalid value {triple<T> t (I, j, a[i*n + j]); _a.push_back (t);   }}}} void  Display () {size_t index = 0;for  (size_t i = 0; i < _m;  ++i) {for  (size_t j = 0; j < _n; ++j) {if  (index<_ A.size () &&i == _a[index]._row && j == _a[index]._col) {cout  << _a[index].value <<  " "; ++index;} else{cout << _invalid <<  " ";}} Cout << endl;} Cout << endl;}  sparsematrix<t> fasttransport ()       //fast Transpose {//Time complexity  o ( Number of valid data +n) SPARSEMATRIX&LT;T&GT;&NBSP;SM (_n, _m, _invalid);  int* rowcounts = new  int[_n];//statistics Number of data memset (rowcounts, 0, sizeof (int) *_n); size_t index = 0; while  (Index < _a.size ()) {Rowcounts[_A[index].col]++;++index;}  int rowStart = new int[_N];rowStart[0] = 0;for  (size_t i =  1; i < _n; ++i) {rowstart[i] = rowstart[i - 1] +  ROWCOUNTS[I&NBSP;-&NBSP;1];}  index = 0;sm._a.resize (_a.size ()) '; '    //cannot use pushbackwhile  (Index < _a.size ())      //_ A.size number of valid data {size_t row = _a[index]._col;int& start = rowstart[row];  Triple<t> t (_a[index]._col, _a[index]._row, _a[index]._value);  sm._a[start] =  t;++start;   // rowstart[row] [value ++++index;} delete[] rowcounts;delete[] &NBSP;ROWSTART;&NBSP;RETURN&NBSP;SM;} protected:        //Storage Ternary Array//triple<t>* _a;         Direct use of dynamic sequential table vector<triple<t>> _a;size_t _m;size_t _n;t _invalid;};  void test2 () {int a[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;SM ((int*) a,6,5,0)  //cast to a one-dimensional array   array  6 row  5 column   illegal value 0SM. Display ();  sparsematrix<int> sM2 = sm. Transport (); sm2. Display ();  sparsematrix<int> sm3 = sm. Fasttransport (); sm3. Display ();}   #include <iostream>using namespace std;  #include <stdlib.h> #include "Matrix.h"  int main () {//test1 (); Test2 (); System ("pause"); return 0;}

Operation Result:

1 0 0 2 0 0

0 0 0 0 0 0

3 0 0 4 0 0

0 0 0 0 0 0

5 0 0 6 0 0

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Transpose and quick transpose of C + + matrices