From 6993ca7375acbd7bd4fb0d5f35439b9e06e622e2 Mon Sep 17 00:00:00 2001
From: superdimensional <plusethunder@gmail.com>
Date: Mon, 19 Apr 2021 02:06:46 -0400
Subject: [PATCH] 2*2 matrix determinant calculator

---
 main.c     |  8 +++++---
 matrices.h | 30 ++++++++++++++++++++++++++++--
 2 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/main.c b/main.c
index c75a91a..e610dd1 100644
--- a/main.c
+++ b/main.c
@@ -13,7 +13,7 @@ int main()
     printf("\n\n  1. Hypotenuse calculator");
     printf("\n  2. Quadratic formula calculator");
     printf("\n  3. Area of a circle");
-    printf("\n  4. * Matrix determinant *");
+    printf("\n  4. Matrix determinant");
     printf("\n  5. Matrix addition");
     printf("\n  6. * Matrix multiplication *");
     printf("\n  7. Scalar matrix multiplication");
@@ -83,8 +83,10 @@ int main()
     case 4:
 
         system("clear");
-        printf("\n ~~ Matrix determinant ~~\n\n");
-
+        printf("\n ~~ 2*2 Matrix determinant ~~\n\n");
+        int det;
+        det = determinant();
+        printf("\nThe determinant is %d!\n",det);
         break;
 
     case 5:
diff --git a/matrices.h b/matrices.h
index be7261f..f21c1fd 100644
--- a/matrices.h
+++ b/matrices.h
@@ -59,10 +59,9 @@ int matrixAddition(int numRows, int numColumns)
 
 int scalarMultiplication(int numRows, int numColumns, int scalar)
 {
-
     int matrix[numRows][numColumns];
 
-    printf("\nEnter elements in matrix of size %d*%d \n", numRows, numColumns);
+    printf("\nEnter elements in matrix of size %d*%d! \n", numRows, numColumns);
 
     for (int i = 0; i < numRows; i++)
     {
@@ -85,6 +84,33 @@ int scalarMultiplication(int numRows, int numColumns, int scalar)
     return 0;
 }
 
+int determinant()
+{
+    int det;
+    int matrix[2][2];
+    printf("\nEnter elements in matrix: \n");
+    for (int i = 0; i < 2; i++)
+    {
+        for (int j = 0; j < 2; j++)
+        {
+            scanf("%d", &matrix[i][j]);
+        }
+    };
+
+    printf("\nElements in matrix are: \n");
+    for (int i = 0; i < 2; i++)
+    {
+        for (int j = 0; j < 2; j++)
+        {
+            printf(" %d ", matrix[i][j]);
+        }
+        printf("\n");
+    }
+
+    det = (matrix[0][0] * matrix[1][1]) - (matrix[0][1] * matrix[1][0]);
+    return det;
+}
+
 // int buildMatrix(int numRows, int numColumns)
 // {