Scala學習常用函數

1.取兩個值的最大公約

def gcp(a: Int, b: Int): Int = if(b==0) a else gcp(b, a%b)

2.階乘，實現類似1*2*3*4*……的計算結果

def fac(n: Int): Int = if(n<=1) 1 else n * fac(n-1)

3.九九乘法表

def multiplication(n: Int) = {
   val p =  for(i <- 1 to n) yield {
                val c =i +"*"+ n +"="+ i*n
                val space =if(i==1) " " else " " * (7-c.length)
                c+space
             }
  p
 }
     
 def multiplicationTable(a: Int=1, b: Int=9)= {
   val beginNumber = if(a<1 || a>9 || a>b) 1 else a
   val endNumber = if(a>9 || b<a) 9 else b
   for(i <- beginNumber to endNumber) yield {
     println(multiplication(i).mkString)
   }
 }
     
multiplicationTable()