From f91525dc5ca1d69db10e9839d36f916199469a1a Mon Sep 17 00:00:00 2001
From: jang-jaehyuk <91679505+jang-jaehyuk@users.noreply.github.com>
Date: Mon, 6 Dec 2021 13:18:00 +0900
Subject: [PATCH] Modify the function to find the determinant

---
 Matrix_Calculator.cpp | 443 ++++++++++++++++++++++--------------------
 1 file changed, 232 insertions(+), 211 deletions(-)

diff --git a/Matrix_Calculator.cpp b/Matrix_Calculator.cpp
index e1d9aaa..da1f1b3 100644
--- a/Matrix_Calculator.cpp
+++ b/Matrix_Calculator.cpp
@@ -14,293 +14,314 @@
 
 using namespace std;
 
+
+
 class Matrix {
-  private:
+private:
     int row, col, scalar;
     int matrix[10][10];
     int result[10][10];
-
-  public:
+    int temp[10][10];
+public:
+    
     // Default Constructor.
     Matrix() {
-      row = 0;
-      col = 0;
-      scalar = 0;
-      for (int i = 0; i < row; i++) {
-        for (int j = 0; j < col; j++) {
-          matrix[i][j] = 0;
-          result[i][j] = 0;
-        }
-      }
+        row = 0;
+        col = 0;
+        scalar = 0;
     }
 
     // Constructor.
     Matrix(int r, int c, int s) {
-      row = r;
-      col = c;
-      scalar = s;
-      for (int i = 0; i < row; i++) {
-        for (int j = 0; j < col; j++) {
-          matrix[i][j] = 0;
-          result[i][j] = 0;
+        row = r;
+        col = c;
+        scalar = s;
+        for (int i = 0; i < row; i++) {
+            for (int j = 0; j < col; j++) {
+                matrix[i][j] = 0;
+                result[i][j] = 0;
+                temp[i][j] = 0;
+            }
         }
-      }
     }
 
     // Operator overload.
     int& operator()(int row, int col) {
-      return matrix[row][col];
+        return matrix[row][col];
+    }
+    int getrow() {
+        return row;
+    }
+    int getcol() {
+        return col;
+    }
+    int getij(int i, int j) {
+        return temp[i][j];
     }
-
     // Get matrix size and populate all matrix elements.
     void getInput() {
-      do {
-        cout << "Rows = ";
-        cin >> row;
-        cout << "Columns = ";
-        cin >> col;
-        if (row < 1 || col < 1 || row > 10 || col > 10) {
-          cout << "Invalid entries. Min size = 1x1 and max size = 10x10.\n";
-        }
-      } while (row < 1 || col < 1 || row > 10 || col > 10);
+        do {
+            cout << "Rows = ";
+            cin >> row;
+            cout << "Columns = ";
+            cin >> col;
+            if (row < 1 || col < 1 || row > 10 || col > 10) {
+                cout << "Invalid entries. Min size = 1x1 and max size = 10x10.\n";
+            }
+        } while (row < 1 || col < 1 || row > 10 || col > 10);
 
-      cout << "Remember to enter matrix entries from top-left to bottom-right.\n";
-      for (int i = 0; i < row; i++) {
-        for (int j = 0; j < col; j++) {
-          cout << "Matrix Entry (" << i << "," << j << ") = ";
-          cin >> matrix[i][j];
+        cout << "Remember to enter matrix entries from top-left to bottom-right.\n";
+        for (int i = 0; i < row; i++) {
+            for (int j = 0; j < col; j++) {
+                cout << "Matrix Entry (" << i << "," << j << ") = ";
+                cin >> matrix[i][j];
+                temp[i][j] = matrix[i][j];
+            }
         }
-      }
     }
-
     // Output the full matrix to the screen in matrix representation.
     void displayMatrix() {
-      for (int i = 0; i < row; i++) {
-        for (int j = 0; j < col; j++) {
-          cout << setw(3) << matrix[i][j];
+        for (int i = 0; i < row; i++) {
+            for (int j = 0; j < col; j++) {
+                cout << setw(3) << matrix[i][j];
+            }
+            cout << endl;
         }
-        cout << endl;
-      }
     }
 
     // Output the full resultant matrix to the screen in matrix representation.
     void displayResultMatrix(int rows, int cols) {
-      for (int i = 0; i < rows; i++) {
-        for (int j = 0; j < cols; j++) {
-          cout << setw(3) << result[i][j];
+        for (int i = 0; i < rows; i++) {
+            for (int j = 0; j < cols; j++) {
+                cout << setw(3) << result[i][j];
+            }
+            cout << endl;
         }
-        cout << endl;
-      }
     }
 
     // Perform scalar multiplication.
     void scalarMultiplication() {
-      cout << "Enter a scalar to multiply the matrix by: ";
-      cin >> scalar;
-      for (int i = 0; i < row; i++) {
-        for (int j = 0; j < col; j++) {
-          matrix[i][j] *= scalar;
+        cout << "Enter a scalar to multiply the matrix by: ";
+        cin >> scalar;
+        for (int i = 0; i < row; i++) {
+            for (int j = 0; j < col; j++) {
+                matrix[i][j] *= scalar;
+            }
         }
-      }
-      displayMatrix();
+        displayMatrix();
     }
 
     // Perform matrix addition.
     void matrixAddition(Matrix m) {
-      if (row == m.row && col == m.col) {
-        for (int i = 0; i < row; i++) {
-          for (int j = 0; j < col; j++) {
-            matrix[i][j] += m(i,j);
-          }
+        if (row == m.row && col == m.col) {
+            for (int i = 0; i < row; i++) {
+                for (int j = 0; j < col; j++) {
+                    matrix[i][j] += m(i, j);
+                }
+            }
+            displayMatrix();
+        }
+        else {
+            cout << "Cannot complete matrix addition with these matrices.\n";
         }
-        displayMatrix();
-      } else {
-        cout << "Cannot complete matrix addition with these matrices.\n";
-      }
     }
 
     // Perform matrix multiplication.
     void matrixMultiplication(Matrix m) {
-      if (col == m.row) {
-        for (int i = 0; i < row; i++) {
-          for (int j = 0; j < m.col; j++) {
-            for (int k = 0; k < m.row; k++) {
-              result[i][j] += matrix[i][k] * m(k,j);
+        if (col == m.row) {
+            for (int i = 0; i < row; i++) {
+                for (int j = 0; j < m.col; j++) {
+                    for (int k = 0; k < m.row; k++) {
+                        result[i][j] += matrix[i][k] * m(k, j);
+                    }
+                }
             }
-          }
+            displayResultMatrix(row, m.col);
+        }
+        else {
+            cout << "Cannot complete matrix multiplication with these matrices.\n";
         }
-        displayResultMatrix(row, m.col);
-      } else {
-        cout << "Cannot complete matrix multiplication with these matrices.\n";
-      }
     }
 
     // Transpose matrix.
     void transpose() {
-      int temp = row;
-      row = col;
-      col = temp;
-      for (int i = 0; i < row; i++) {
-        for (int j = 0; j < col; j++) {
-          result[i][j] = matrix[j][i];
+        int temp = row;
+        row = col;
+        col = temp;
+        for (int i = 0; i < row; i++) {
+            for (int j = 0; j < col; j++) {
+                result[i][j] = matrix[j][i];
+            }
         }
-      }
-      displayResultMatrix(row, col);
+        displayResultMatrix(row, col);
     }
 
     // Swaps two rows.
     void swapRows(int row1, int row2) {
-      if (row1 < row && row2 < row) {
-        int temp[1][col];
-        for (int i = 0; i < col; i++) {
-          temp[0][i] = matrix[row1][i];
-          matrix[row1][i] = matrix[row2][i];
-          matrix[row2][i] = temp[0][i];
+        if (row1 < row && row2 < row) {
+            int *temp = new int[row];   //동적할당으로 생성해야함
+            for (int i = 0; i < col; i++) {
+                temp[i] = matrix[row1][i];
+                matrix[row1][i] = matrix[row2][i];
+                matrix[row2][i] = temp[i];
+            }
+        }
+        else {
+            cout << "Could not access specified row to swap.\n";
         }
-      } else {
-        cout << "Could not access specified row to swap.\n";
-      }
     }
 
     // Compute the reduced row-echelon form of a matrix.
     void matrixRREF() {
-      int lead = 0;
-      for (int r = 0; r < row; r++) {
-        if (lead >= col) {
-          return;
-        }
-        int i = r;
-        while (matrix[i][lead] == 0) {
-          i += 1;
-          if (i == row) {
-            i = r;
-            lead += 1;
-            if (col == lead) {
-              return;
+        int lead = 0;
+        for (int r = 0; r < row; r++) {
+            if (lead >= col) {
+                return;
             }
-          }
-        }
-        swapRows(i, r);
-        int val = matrix[r][lead];
-        if (matrix[r][lead] != 0) {
-          for (int j = 0; j < col; j++) {
-            matrix[r][j] /= val;
-          }
+            int i = r;
+            while (matrix[i][lead] == 0) {
+                i += 1;
+                if (i == row) {
+                    i = r;
+                    lead += 1;
+                    if (col == lead) {
+                        return;
+                    }
+                }
+            }
+            swapRows(i, r);
+            int val = matrix[r][lead];
+            if (matrix[r][lead] != 0) {
+                for (int j = 0; j < col; j++) {
+                    matrix[r][j] /= val;
+                }
+            }
+            for (int i = 0; i < row; i++) {
+                if (i != r) {
+                    int val = matrix[i][lead];
+                    for (int j = 0; j < col; j++) {
+                        matrix[i][j] -= (val * matrix[r][j]);
+                    }
+                }
+            }
+            lead += 1;
         }
+        displayMatrix();
+    }
+
+    // TODO: Finds the determinant of a matrix. 
+    int determinantFinder(int n) {
+        int determinant = 0;
+        int matrix[10][10];
         for (int i = 0; i < row; i++) {
-          if (i != r) {
-            int val = matrix[i][lead];
             for (int j = 0; j < col; j++) {
-              matrix[i][j] -= (val * matrix[r][j]);
+                matrix[i][j] = getij(i, j);
             }
-          }
         }
-        lead += 1;
-      }
-      displayMatrix();
-    }
-
-    // TODO: Finds the determinant of a matrix.
-    int determinantFinder() {
-      if (col == row) {
-        int determinant;
-        if (row == 1) {
-          determinant = matrix[0][0];
-        } else if (row == 2) {
-          determinant = (matrix[0][0] * matrix[1][1]) - (matrix[0][1] * matrix[1][0]);
-        } else {
-          for (int p = 0; p < row; p++) {
-            int h = 0,
-              k = 0;
-            for (int i = 1; i < row; i ++) {
-              for (int j = 0; j < n; j++) {
-                if (j == p) {
-                  continue;
-                }
-                // temp[h][k] = matrix[i][j];
-                k++;
-                if (k == n - 1) {
-                  h++;
-                  k = 0;
+        if (n == 2) {
+            return (matrix[0][0] * matrix[1][1]) - (matrix[0][1] * matrix[1][0]);
+        }
+        else {
+            for (int p = 0; p < n; p++) {
+                int h = 0;
+                for (int i = 1; i < n; i++) {
+                    int k = 0;
+                    for (int j = 0; j < n; j++) {
+                        if (j == p) {
+                            continue;
+                        }
+                        temp[h][k] = matrix[i][j];
+                        k++;
+                    }
+                    h++;
                 }
-              }
+                determinant = determinant + matrix[0][p] * pow(-1, p) * determinantFinder(n - 1);
             }
-            //determinant = determinant + matrix[0][p] * pow(-1, p) * determinantFinder(temp, n -1);
-          }
-          //return determinant;
         }
-        cout << "The determinant of this matrix is: " << determinant << endl;
-      } else {
-        cout << "Cannot find the determinant of this matrix. (Must be nxn)\n";
-      }
+        return determinant;
     }
 
     // TODO: Inverses a matrix.
     void inverseMatrix() {
-      if (col == row) {
-        //TODO
-      } else {
-        cout << "Cannot invert this matrix. (Must be nxn)\n";
-      }
+        if (col == row) {
+            //TODO
+        }
+        else {
+            cout << "Cannot invert this matrix. (Must be nxn)\n";
+        }
     }
 };
 
-int main () {
-  cout << "Welcome to Matrix Calculator V1.1 By Baraa Hamodi!\n\n"
-     << "Start by making your first matrix!\n";
-  Matrix a;
-  a.getInput();
-  int choice;
-  string proceed, remakeMatrix;
-  cout << "Now that you have this matrix:\n";
-  a.displayMatrix();
-  cout << "What would you like to do?\n"
-     << "Enter 1 for matrix scalar multiplication.\n"
-     << "Enter 2 for matrix addition.\n"
-     << "Enter 3 for matrix multiplication.\n"
-     << "Enter 4 to find the matrix determinant.\n"
-     << "Enter 5 to transpose the matrix.\n"
-     << "Enter 6 to find the inverse of your matrix.\n"
-     << "Enter 7 to put your matrix in RREF.\n";
-  do {
-    cout << "Please enter your operation choice: ";
-    cin >> choice;
-    if (choice == 1) {
-      a.scalarMultiplication();
-    } else if (choice == 2) {
-      cout << "This will require a second matrix, please create one now.\n";
-      Matrix b;
-      b.getInput();
-      a.matrixAddition(b);
-    } else if (choice == 3) {
-      cout << "This will require a second matrix, please create one now.\n";
-      Matrix b;
-      b.getInput();
-      a.matrixMultiplication(b);
-    } else if (choice == 4) {
-      a.determinantFinder();
-    } else if (choice == 5) {
-      a.transpose();
-    } else if (choice == 6) {
-      a.inverseMatrix();
-    } else if (choice == 7) {
-      a.matrixRREF();
-    }
-    cout << "Continue? (Enter yes or no) ";
-    cin >> proceed;
-    transform(proceed.begin(), proceed.end(), proceed.begin(), ::tolower);
-    if (proceed == "yes") {
-      cout << "Now enter yes to create a new matrix or no to use current matrix.\n";
-      cin >> remakeMatrix;
-      transform(remakeMatrix.begin(), remakeMatrix.end(), remakeMatrix.begin(), ::tolower);
-      if (remakeMatrix == "yes") {
-        a.getInput();
-      }
-    }
-  } while(proceed == "yes");
+int main() {
+    cout << "Welcome to Matrix Calculator V1.1 By Baraa Hamodi!\n\n"
+        << "Start by making your first matrix!\n";
+    Matrix a;
+    a.getInput();
+    int choice;
+    string proceed, remakeMatrix;
+    cout << "Now that you have this matrix:\n";
+    a.displayMatrix();
+    cout << "What would you like to do?\n"
+        << "Enter 1 for matrix scalar multiplication.\n"
+        << "Enter 2 for matrix addition.\n"
+        << "Enter 3 for matrix multiplication.\n"
+        << "Enter 4 to find the matrix determinant.\n"
+        << "Enter 5 to transpose the matrix.\n"
+        << "Enter 6 to find the inverse of your matrix.\n"
+        << "Enter 7 to put your matrix in RREF.\n";
+    do {
+        cout << "Please enter your operation choice: ";
+        cin >> choice;
+        if (choice == 1) {
+            a.scalarMultiplication();
+        }
+        else if (choice == 2) {
+            cout << "This will require a second matrix, please create one now.\n";
+            Matrix b;
+            b.getInput();
+            a.matrixAddition(b);
+        }
+        else if (choice == 3) {
+            cout << "This will require a second matrix, please create one now.\n";
+            Matrix b;
+            b.getInput();
+            a.matrixMultiplication(b);
+        }
+        else if (choice == 4) {
+            int row = a.getrow();
+            int col = a.getcol();    
+            if(row == col){
+                int det = a.determinantFinder(row);
+                cout << "The determinant of this matrix is: " << det << endl;
+            }
+            else {
+                 cout << "Cannot find the determinant of this matrix. (Must be nxn)\n";
+            }
+        }
+        else if (choice == 5) {
+            a.transpose();
+        }
+        else if (choice == 6) {
+            a.inverseMatrix();
+        }
+        else if (choice == 7) {
+            a.matrixRREF();
+        }
+        cout << "Continue? (Enter yes or no) ";
+        cin >> proceed;
+        transform(proceed.begin(), proceed.end(), proceed.begin(), ::tolower);
+        if (proceed == "yes") {
+            cout << "Now enter yes to create a new matrix or no to use current matrix.\n";
+            cin >> remakeMatrix;
+            transform(remakeMatrix.begin(), remakeMatrix.end(), remakeMatrix.begin(), ::tolower);
+            if (remakeMatrix == "yes") {
+                a.getInput();
+            }
+        }
+    } while (proceed == "yes");
 
-  system("PAUSE");
-  return EXIT_SUCCESS;
+    system("PAUSE");
+    return EXIT_SUCCESS;
 }
 
 /*******************************************************************************