object MatrixMultiplicationManual {
def multiplyMatrices(matrix1: Array[Array[Int]], matrix2: Array[Array[Int]]): Array[Array[Int]] = {
val rows1 = matrix1.length
val cols1 = matrix1(0).length
val rows2 = matrix2.length
val cols2 = matrix2(0).length
if (cols1 != rows2) {
throw new IllegalArgumentException("Matrices cannot be multiplied: incompatible dimensions.")
}
val result = Array.ofDim[Int](rows1, cols2)
for (i <- 0 until rows1) {
for (j <- 0 until cols2) {
for (k <- 0 until cols1) {
result(i)(j) += matrix1(i)(k) * matrix2(k)(j)
}
}
}
result
}
def main(args: Array[String]): Unit = {
val matrix1 = Array(
Array(1, 2, 3),
Array(4, 5, 6),
Array(7, 8, 9)
)
val matrix2 = Array(
Array(4, 6),
Array(7, 3),
Array(1, 2)
)
try {
val result = multiplyMatrices(matrix1, matrix2)
result.foreach(row => println(row.mkString(" ")))
} catch {
case e: IllegalArgumentException => println(e.getMessage)
}
}
}
/*
run:
21 18
57 51
93 84
*/
