fun multiplyMatrices(matrix1: Array<DoubleArray>, matrix2: Array<DoubleArray>): Array<DoubleArray> {
val rows1 = matrix1.size
val cols1 = matrix1[0].size
val rows2 = matrix2.size
val cols2 = matrix2[0].size
if (cols1 != rows2) {
throw IllegalArgumentException("Matrices cannot be multiplied: incompatible dimensions.")
}
val result = Array(rows1) { DoubleArray(cols2) }
for (i in 0 until rows1) {
for (j in 0 until cols2) {
for (k in 0 until cols1) {
result[i][j] += matrix1[i][k] * matrix2[k][j]
}
}
}
return result
}
fun main() {
val matrix1 = arrayOf(
doubleArrayOf(1.0, 2.0, 3.0),
doubleArrayOf(4.0, 5.0, 6.0),
doubleArrayOf(7.0, 8.0, 9.0)
)
val matrix2 = arrayOf(
doubleArrayOf(4.0, 6.0),
doubleArrayOf(7.0, 3.0),
doubleArrayOf(1.0, 2.0)
)
try {
val mul = multiplyMatrices(matrix1, matrix2)
mul.forEach { row -> println(row.joinToString(" ")) }
} catch (e: IllegalArgumentException) {
println(e.message)
}
}
/*
run:
21.0 18.0
57.0 51.0
93.0 84.0
*/
