old c,cc examples

1 files changed, 210 insertions, 0 deletions

diff --git a/c,cc/matrix.cc b/c,cc/matrix.cc
new file mode 100644
index 0000000..9d1a1c0
--- /dev/null
+++ b/c,cc/matrix.cc
@@ -0,0 +1,210 @@
+#include <iostream>
+#include <stdlib.h>
+
+using namespace std;
+
+
+class MyMatrix
+{
+  public:
+    MyMatrix(int dimension);
+    MyMatrix(int rows, int columns);
+    ~MyMatrix();
+
+    void print();
+    int get_rows();
+    int get_columns();
+
+    double get_element(int row, int column);
+    void set_element(int row, int column, double value);
+
+    MyMatrix operator + (MyMatrix A);
+    MyMatrix operator * (MyMatrix A);
+    void operator = (MyMatrix A);
+
+
+  private:
+    double* m;
+    int row_d;
+    int col_d;
+    int d;
+};
+
+MyMatrix::MyMatrix(int dimension)
+{
+  row_d = dimension;
+  col_d = dimension;
+  d = dimension*dimension;
+  m = new double[d];
+
+  unsigned int k=0;
+  for(unsigned int i=0; i<row_d; i++) {
+    for(unsigned int j=0; j<col_d; j++) {
+      if(i==j) {
+          m[k] = 1;
+      } else {
+        m[k] = 0;
+      }
+      k++;
+    }
+  }
+}
+
+MyMatrix::MyMatrix(int rows, int columns)
+{
+  row_d = rows;
+  col_d = columns;
+  d = rows*columns;
+  m = new double[d];
+
+
+  srand(time(NULL));
+  for(unsigned int i=0; i<d; i++) {
+    m[i] = 1+(rand()%(100-1+1));
+  }
+}
+
+MyMatrix::~MyMatrix()
+{
+  delete[] m;
+}
+
+void MyMatrix::print()
+{
+  unsigned int k=0;
+  for(unsigned int i=0; i<row_d; i++) {
+    for(unsigned int j=0; j<col_d; j++) {
+      cout << m[k] << " ";
+      k++;
+    }
+    cout << endl;
+  }
+}
+
+int MyMatrix::get_rows()
+{
+  return row_d;
+}
+
+int MyMatrix::get_columns()
+{
+  return col_d;
+}
+
+
+double MyMatrix::get_element(int row, int column)
+{
+  // first element is 1,1!
+  if((row*column)<=0) {
+    return -1;
+  }
+  return m[((row-1)*col_d)+(column-1)];
+}
+
+void
+MyMatrix::set_element(int row, int column, double value)
+{
+  if((row*column)>0) {
+    m[((row-1)*col_d)+(column-1)] = value;
+  }
+}
+
+
+MyMatrix
+MyMatrix::operator + (MyMatrix A)
+{
+  MyMatrix* res = new MyMatrix(row_d, col_d);
+
+  unsigned int k=0;
+  for(unsigned int i=0; i<row_d; i++) {
+    for(unsigned int j=0; j<col_d; j++) {
+      res->m[k] = m[k]+A.get_element(i+1, j+1);
+      k++;
+    }
+  }
+
+  return *res;
+}
+
+MyMatrix MyMatrix::operator * (MyMatrix A)
+{
+  MyMatrix* res = new MyMatrix(row_d, col_d);
+
+  unsigned int k=0;
+  for(unsigned int i=0; i<row_d; i++) {
+    for(unsigned int j=0; j<col_d; j++) {
+      res->m[k] = m[k]*A.get_element(i+1, j+1);
+      k++;
+    }
+  }
+
+  return *res;
+}
+
+void MyMatrix::operator = (MyMatrix A)
+{
+  unsigned int k=0;
+  for(unsigned int i=0; i<A.get_rows(); i++) {
+    for(unsigned int j=0; j<A.get_columns(); j++) {
+      m[k] = A.get_element(i+1, j+1);
+      k++;
+    }
+  }
+}
+
+
+int main (int argc, char* const argv[]) {
+  cout << "9x9 identity matrix:" << endl;
+  MyMatrix* m = new MyMatrix(9);
+  m->print();
+
+  cout << "   rows: " << m->get_rows() << ", ";
+  cout << "columns: " << m->get_columns() << endl;
+
+  delete m;
+
+
+  cout << endl << "2x5 matrix:" << endl;
+  MyMatrix n(2,5);
+  n.print();
+
+  cout << "   rows: " << n.get_rows() << ", ";
+  cout << "columns: " << n.get_columns() << endl;
+
+  cout << "(1,3) = " << n.get_element(1,3) << endl;
+
+  cout << "last: (2,5) = " << n.get_element(2,5) << endl;
+
+  cout << "second to last element = 100: " << endl;
+  n.set_element(2, 4, 100);
+  n.print();
+
+  cout << endl << "addition:" << endl;
+  cout << "matrix 1:" << endl;
+  MyMatrix* a1 = new MyMatrix(3,3);
+  a1->print();
+  cout << "matrix 2:" << endl;
+  MyMatrix* a2 = new MyMatrix(3,3);
+  a2->print();
+  cout << "result:" << endl;
+  MyMatrix* e1 = new MyMatrix(3,3);
+  *e1 = *a1+*a2;
+  e1->print();
+  delete e1;
+
+  cout << endl << "multiplication" << endl;
+  cout << "matrix 1:" << endl;
+  MyMatrix* m1 = new MyMatrix(3,3);
+  a1->print();
+  cout << "matrix 2:" << endl;
+  MyMatrix* m2 = new MyMatrix(3,3);
+  m2->print();
+  cout << "result:" << endl;
+  MyMatrix* e2 = new MyMatrix(3,3);
+  *e2 = *m1 * *m2;
+  e2->print();
+  delete e2;
+
+  return 0;
+}
+