object Plalindrome {
  val hwrst=new scala.collection.mutable.ArrayBuffer[String]()
  def accMaxPos(index:Int,len: Int):(Int,Int)={
    val isOddlen=(len-1-index+1)%2==1 //index到末尾的元素个数是否为奇偶
    val pos=(len-1-index)/2
    if(isOddlen){
      return (pos,pos)
    }else{
      return (pos,pos+1)
    }

  }
  def appendPartplalindrome(index:Int,str:String){
    //get from index to end the biggest pos
    val len=str.length
    val ( lmaxpos , rmaxpos )=accMaxPos(index,len)
    val maxlenisOdd=lmaxpos==rmaxpos
    //index fixed but pos moves from 0 to lmaxpos indices the new middle point relative length to index.
    for(i <- 0 until lmaxpos){
      if(i==0){
        if(str(index)==str(index+1)){
          hwrst.append(str.substring(index,index+1+1)) // 需要再加1才可以
        }

      }else if(i==lmaxpos && !maxlenisOdd && lmaxpos>0){
        if(str.substring(index,index+lmaxpos+1) == str.substring(rmaxpos).reverse){
          hwrst.append(str.substring(index))
        }
      }else{
        if(str.substring(index,index+i) == str.substring(index+i+1,index+2*i+1).reverse){
          hwrst.append(str.substring(index,index+2*i+1))
        }
      }
    }



  }

  def getAllplalindrome(str:String){

    // pre check str.len if >1
    val len=str.length
    if(len < 2) return
    //index 最大只能偏移到倒数第二个位置
    for(index <- 0 until len-1){
      appendPartplalindrome(index,str)
    }

    hwrst.map(println)

  }


  def main(args: Array[String]): Unit = {
   val str1="caabaacddaweqweradfadqwerqwerqweradfqwerqwerqweradfqfdarewqrewqrewqfewrrqwerwerdfasdqweeasdqwerqwerqweadsfqewrqwerqwefadfqer"
    getAllplalindrome(str1)
}
}