Fixed Matrix Multiplication Bugs

MatrixExample.java

@@ -8,24 +8,22 @@ public static void main(String[] args) {
                 { 27, 8, 9, 5, 3, 21 },
                 { 73, 2, 19, 5, 1, 8 },
                 { 47, 9, 9, 5, 0, 22 },
-                { 78, 86, 1, 4, 1, 21 },
-                { 73, 18, 2, 2, 5, 11 }
+                { 78, 86, 1, 4, 1, 21 }
         };
 
         int numRows = 6;
-        int numCols = 7;
+        int numCols = 6; // Corrected the column size to match matrix1's column size
 
-        int[][] matrix2 = generateRandomMatrix(numRows, numCols);
+        int[][] matrix2 = generateRandomMatrix(numCols, numRows); // Fixed dimensions to match for multiplication
         int[][] result = multiplyMatrices(matrix, matrix2);
 
         System.out.println("result length: " + result.length + " x " + result[0].length);
         for (int i = 0; i < result.length; i++) {
-            for (int j = 0; j < result[i].length; i++) {
+            for (int j = 0; j < result[i].length; j++) { // Fixed the loop here to use j instead of i
                 System.out.print(result[i][j] + " ");
             }
             System.out.println();
         }
-
     }
 
     public static int[][] multiplyMatrices(int[][] matrix1, int[][] matrix2) {
@@ -39,14 +37,12 @@ public static int[][] multiplyMatrices(int[][] matrix1, int[][] matrix2) {
                     "Number of columns in the first matrix must be equal to the number of rows in the second matrix.");
         }
 
-        // Some more issues here too
-        int[][] result = new int[rows1+1][cols2+1];
+        int[][] result = new int[rows1][cols2];
 
-        // Lots of issues with this code, it used to be working perfectly though
         for (int i = 0; i < rows1; i++) {
             for (int j = 0; j < cols2; j++) {
                 for (int k = 0; k < cols1; k++) {
-                    result[j][k] += matrix1[i][j] * matrix2[k][j];
+                    result[i][j] += matrix1[i][k] * matrix2[k][j];
                 }
             }
         }
@@ -66,5 +62,4 @@ public static int[][] generateRandomMatrix(int numRows, int numCols) {
 
         return matrix;
     }
-
 }

Tester.java

@@ -0,0 +1,26 @@
+public class Tester {
+    public static void main(String[] args){
+        int[][] matrix = {
+                { 1, 2, 3, 4, 5, 6 },
+                { 4, 5, 6, 3, 7, 2 },
+                { 27, 8, 9, 5, 3, 21 },
+                { 73, 2, 19, 5, 1, 8 },
+                { 47, 9, 9, 5, 0, 22 },
+                { 78, 86, 1, 4, 1, 21 }
+        };
+
+        int numRows = 6;
+        int numCols = 6; // Corrected the column size to match matrix1's column size
+
+        int[][] matrix2 = MatrixExample.generateRandomMatrix(numCols, numRows); // Fixed dimensions to match for multiplication
+        int[][] result = MatrixExample.multiplyMatrices(matrix, matrix2);
+
+        System.out.println("result length: " + result.length + " x " + result[0].length);
+        for (int i = 0; i < result.length; i++) {
+            for (int j = 0; j < result[i].length; j++) { // Fixed the loop here to use j instead of i
+                System.out.print(result[i][j] + " ");
+            }
+            System.out.println();
+        }
+    }
+}