From e249ebe4e3be4c85d99be53cb786ad81878b9ed7 Mon Sep 17 00:00:00 2001
From: Reshief Luminon <reshief@gmx.net>
Date: Tue, 22 Oct 2019 04:07:05 +0200
Subject: [PATCH] Add sample with custom class and more complex operations
---
src/matrix.h | 65 +++++++++++++++++++++++++++++++++++++++++++++
src/sample_4.cpp | 68 ++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 133 insertions(+)
create mode 100644 src/matrix.h
create mode 100644 src/sample_4.cpp
diff --git a/src/matrix.h b/src/matrix.h
new file mode 100644
index 0000000..8db2dd9
--- /dev/null
+++ b/src/matrix.h
@@ -0,0 +1,65 @@
+#ifndef __MATRIX_H__
+#define __MATRIX_H__
+#include <vector>
+#include <iostream>
+
+namespace magic {
+ using std::vector;
+
+ // This is a custom Matrix type to allow for matrix multiplication
+ class Matrix {
+ public:
+ Matrix(uint8_t rows, uint8_t columns) {
+ this->_rows = rows;
+ this->_columns = columns;
+ this->entries.assign(rows, vector<int32_t>(columns, 0));
+ }
+
+ void setValue(uint8_t i, uint8_t j, int32_t value) {
+ entries[i][j] = value;
+ }
+
+ int32_t getValue(uint8_t i, uint8_t j) {
+ return entries[i][j];
+ }
+
+ // Calculate the matrix product with another matrix
+ Matrix multiply(Matrix &other) {
+ // Create the result matrix
+ Matrix result(this->_rows, other._columns);
+
+ // Calculate all entries in the resulting matrix
+ for (uint8_t r = 0; r < this->_rows; r++) {
+ for (uint8_t c = 0; c < other._columns; c++) {
+ for (uint8_t link = 0; link < this->_columns; link++) {
+ int32_t res = result.getValue(r, c) + this->getValue(r, link) * other.getValue(link, c);
+ result.setValue(r, c, res);
+ }
+ }
+ }
+
+ // Return the resulting matrix
+ return result;
+ }
+
+ // Output the matrix to screen
+ void print() {
+ using std::cout;
+ using std::endl;
+
+ for (uint8_t r = 0; r < this->_rows; r++) {
+ for (uint8_t c = 0; c < this->_columns; c++) {
+ cout << entries[r][c] << '\t';
+ }
+ cout << endl;
+ }
+ }
+
+ private:
+ uint8_t _rows;
+ uint8_t _columns;
+ vector<vector<int32_t>> entries;
+ };
+}
+
+#endif
\ No newline at end of file
diff --git a/src/sample_4.cpp b/src/sample_4.cpp
new file mode 100644
index 0000000..b466ac5
--- /dev/null
+++ b/src/sample_4.cpp
@@ -0,0 +1,68 @@
+#include "matrix.h"
+#include <iostream>
+
+// A simple program to multiply to matrices read in from std input
+
+int main(int argc, char **argv) {
+ using std::cin;
+ using std::cout;
+ using std::cerr;
+ using std::endl;
+
+ uint8_t rows1, columns1;
+ cout << "Number of rows of the first matrix" << endl;
+ cin >> rows1;
+ cout << "Number of columns of the first matrix" << endl;
+ cin >> columns1;
+
+ // Import our custom Matrix type
+ using magic::Matrix;
+
+ Matrix matrix_1(rows1, columns1);
+
+ cout << "Please enter the entries of the matrix in a row-after-row fashion with spaces separating subsequent entries" << endl;
+ for (uint8_t r = 0; r < rows1; r++) {
+ for (uint8_t c = 0; c < columns1; c++) {
+ int32_t val;
+ cin >> val;
+ matrix_1.setValue(r, c, val);
+ }
+ }
+
+ cout << "Matrix 1 was read:" << endl;
+ matrix_1.print();
+
+
+ uint8_t rows2, columns2;
+ cout << "Number of rows of the second matrix" << endl;
+ cin >> rows2;
+
+ if (rows2 != columns1) {
+ cerr << "The number of rows in the second matrix has to equal the number of columns in the first matrix" << endl;
+ // Declare an error and stop execution
+ exit(1);
+ }
+ cout << "Number of columns of the second matrix" << endl;
+ cin >> columns2;
+
+ Matrix matrix_2(rows2, columns2);
+
+ cout << "Please enter the entries of the matrix in a row-after-row fashion with spaces separating subsequent entries" << endl;
+ for (uint8_t r = 0; r < rows2; r++) {
+ for (uint8_t c = 0; c < columns2; c++) {
+ int32_t val;
+ cin >> val;
+ matrix_2.setValue(r, c, val);
+ }
+ }
+
+ cout << "Matrix 2 was read:" << endl;
+ matrix_2.print();
+
+ Matrix product = matrix_1.multiply(matrix_2);
+
+ cout << "M1 * M2 =" << endl;
+ product.print();
+
+ return 0;
+}
\ No newline at end of file
--
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