From cefa54cf51a2bb7e1265590111144eafba7bce13 Mon Sep 17 00:00:00 2001
From: Joanna <jwu2@hwemail.com>
Date: Tue, 4 Nov 2025 13:12:43 -0800
Subject: [PATCH] Updated MatrixExample.java

Added testers and fixed methods
---
 MatrixExample.class | Bin 0 -> 3000 bytes
 MatrixExample.java  |  64 +++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 57 insertions(+), 7 deletions(-)
 create mode 100644 MatrixExample.class

diff --git a/MatrixExample.class b/MatrixExample.class
new file mode 100644
index 0000000000000000000000000000000000000000..1051fcd73453562c5f7903d44d337c6ba4070e4c
GIT binary patch
literal 3000
zcmaJ@OK%(389kTtA}PwIC68?C5i_<`OQcMtO3c($Bu7^4n6V@}p`w(wQ)fhtB}U{7
zLk?Ye(Vcb$y6pp~69_0;v{|%W*n-_Ms{%!f{(_?DqCgi#mjwa{PTg~7Xqm3n5}f<^
z=G^af&v)<q;olG20Nz45iVze7Y7825f%wPP9c!{`IqQ>!)sOA6C!oJkaVp-dfHF3|
zVjwIKx{;3}iXH>87<zF?pm)*o8kMa}TUM=JwFQo@+m79^Jo`P%S#xW_TLEJ%pC7*w
ztd7TU1bwtvYgN5Uy?WONmF=cL&loZMOK1c~VHy~S;TVoT=U?$|)3a-I%Wct1bHVq#
z;!a*`R2;A9HEgRk-NzsYV;I7)z_FUOY0tY(+44T9cpDrwJ<IWEZ$P>gtoI}5;)=6A
z9mPvHVIUd9%Qz{}e}DmoRF~$e4m}uqQN{R59|TTI4@M>8f0;QG!<e+8`P!u6l(eeL
zG*85E78!w<XE(jYPO>=dBuVCJMdDtG;p>>{;NI@!pDJZ=KH#+&&LK-ldBZMm3Phf!
z`Fa@NU?kV9X478F7|02ne8z)(wQ8?h)w#xct7bdirLD4E_bRRv#v1~+mRhw{yODHn
zC(CZNRdbrjij(v<?BwlAqv<7UJ};8B7RRf0(*C4nRg<3UBb@!E4foso>za1ib=Eoy
zGf|w!tmNiN18;J#8LfefPkGStD%Ht=Vo}UNk!Ut^xE#aVxWbqmd&|o^<cG@K=h@A>
zYvkwQg^FVbt}k1wlCf&ds&Eqr#%>(6i)47wv&x%`R^7)ND3A~bKn0>jx78@ymn%|h
z-*a`5kx8ZR7hTtDdJU_-XnPy(S~HAgmQ2HLa&wba+gbNEa!HZgN{TR6SZ*SDSjRV`
zDB-$+8<I>nNvdZ%RB`UOoAzWt+koMht+MAf?h5>%o0T14VD<`2vuZa_FSzbzt3Lf=
z*j<w67B1hd+XukAvk{yf)7?eYQ88~-tHp|EPm`#5hlj*`Rno3$;FiGX3o#w!ssSeP
zrT-7*u@%I{Dw0Q>{244o9&&8+oQ<#-?6uSbh+lCa@D5w~8c-0yRV;8!sB)D{4+EiJ
z#Esv=C@FFMH_?)!7D}pCC~113q#K2j5iXR%alKG1slj{7RLV5UN;)4SPDxlJfFh|N
zK14*^heQbBz#uFfHwn=@kbK8TyuX8>)iBo-sV-15DV1=&CL3RgA|V5W&>i2-l7y@f
z!o|L;z7lCB-fbt|M+hU*`2^AQ6p9OReI{<q4v*|2l2g+Obr*+o+ON@{(Ao)2nQA{o
z0=SP6C99h{g*(V9S;I6EnyF85Htb_LHjT_foRZkDZ5!gJPyWgm_c6Y$bNqYFPwao?
zm8tY4U70NAblrz)eq{2EpA9vbGX-iq%D}W>-XrI+LNR9q1_EhLO5Y?ZSak&7rQisD
zL|izbCyYdR7wN7A%!jJ%!<k<0dodU3LIhlRs*t;=8bn095K;$a9g~t1zT>%`L?jVS
z^w6N{$EC`+$f8`VYc7@bcFp~e4kcoV-ozoU<SrV!n2fK**Vw5V8%gMpPw3lnf5`iP
zk-}dhjy+zwJi9~$rWnRCafa9GIV8jt_DdKN%amQm3GoO?@i)9I{)tneS8zJCjM31C
zI1~B~#zNo2c<B3>2;IZk&`*#F{T!26q?MCUpNJDM3@jPAAOsuP1CJ3EdpNa+9#$hS
zp`fsEkA<dk-KA7J-ToAs^0_iIoFZw?rG}^4X+D8)c0|s1aGc#phVqe&|6*GqcmBQ|
zV*5w+^Zk%BGy_brYF}j?pW}B%7Q=X*x9WLbvpGtpIXjOTj^=T}cfB7*<S~Tklg+>$
zH2&!;Z{Citv+_fUYRy!dB`~pzSAU2eQn>GRlK)w{5BZ>Z#Q1S_6qkM73dB+B;_ckg
zRp{s%8609+El#utKSTcni)rYygLL-!Ny_tVdWSl%GL}VOZy4e+hM8eT$#1ES@-K;t
z($PDq_DqU8XVdMhn&u#@jhO1E=zWCqrM~G0nE7JZ)P9Exp`7kl?C=gQD%r3ZHnkm0
zDcOh_8QH<9gl-yBX82|%CHqJwZALiFY<yJMjxh0m*$%V)lV8&9g#OF@U6_?;Cay6b
z?;?!%n2{oVd>_ZLLZVzp8aMG8KEy1(#mo8@EcWZ1*C=md&5tk*;|alfhe(3V#aHsf
z^8zCe^NEmFqn+J~$Zye35`M;%=`_DEI3y!ne1y5u1I#ZC-h(mpWAw-zJiuFDC|T81
z2X`>4WHnP8+QGntsZN>N+4$OhTq<m9jO`!WD%(F#JPR%5CwPMdt1!q-ewtQs0xro_
z=PrN3km}rim)q6y!x)7A6^{8q%o&e)p-boYa9nasVTxp}zRMJW{)g}ZV<`IV`%DLD
MOE5JbVHJu00P(MgJpcdz

literal 0
HcmV?d00001

diff --git a/MatrixExample.java b/MatrixExample.java
index 051e5bc..a595c35 100644
--- a/MatrixExample.java
+++ b/MatrixExample.java
@@ -18,14 +18,62 @@ public static void main(String[] args) {
         int[][] matrix2 = generateRandomMatrix(numRows, numCols);
         int[][] result = multiplyMatrices(matrix, matrix2);
 
-        System.out.println("result length: " + result.length + " x " + result[0].length);
+        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++) {
                 System.out.print(result[i][j] + " ");
             }
             System.out.println();
         }
 
+        // test Multiply
+        int[][] a = { { 1, 2, 3 }, { 4, 5, 6 } }, b = { { 7, 8 }, { 9, 10 }, { 11, 12 } };
+        int[][] c = { { 58, 64 }, { 139, 154 } };
+        testMultiply(a, b, c);
+
+        int[][] a1 = { { 2, 0 }, { 0, 2 } }, b1 = { { 1, 2 }, { 3, 4 } };
+        int[][] c1 = { { 2, 4 }, { 6, 8 } };
+        testMultiply(a1, b1, c1);
+
+        int[][] a2 = { { 3 } }, b2 = { { 4 } };
+        int[][] c2 = { { 12 } };
+        testMultiply(a2, b2, c2);
+
+        // test Generate
+        testGenerate(6, 7);
+        testGenerate(100, 100);
+        testGenerate(1, 2);
+    }
+
+    private static boolean check(int[][] x, int[][] y) {
+        if (x.length != y.length) {
+            return false;
+        }
+        for (int i = 0; i < x.length; i++) {
+            if (x[i].length != y[i].length) {
+                return false;
+            }
+            for (int j = 0; j < x[i].length; j++) {
+                if (x[i][j] != y[i][j]) {
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
+
+    private static void testMultiply(int[][] a, int[][] b, int[][] result) {
+        if (check(multiplyMatrices(a, b), result)) {
+            System.out.println("Passed.");
+        }
+    }
+
+    private static void testGenerate(int rows, int cols) {
+        int[][] m = generateRandomMatrix(rows, cols);
+        if (m.length == rows && m[0].length == cols) {
+            System.out.println("Passed.");
+        }
     }
 
     public static int[][] multiplyMatrices(int[][] matrix1, int[][] matrix2) {
@@ -39,14 +87,12 @@ 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];
                 }
             }
         }
@@ -58,9 +104,13 @@ public static int[][] generateRandomMatrix(int numRows, int numCols) {
         int[][] matrix = new int[numRows][numCols];
         Random random = new Random();
 
+        if (numRows <= 0 || numCols <= 0) {
+            throw new IllegalArgumentException();
+        }
+
         for (int i = 0; i < numRows; i++) {
             for (int j = 0; j < numCols; j++) {
-                matrix[i][j] = random.nextInt(100); // Generates random values between 0 and 99
+                matrix[i][j] = random.nextInt(100);
             }
         }