<template>
  <div id="testActivity" class="main">
    <el-form :model="form" class="demo-form-inline">
      <el-form-item label="">
        <el-input v-model="form.value" placeholder="請輸入要排隊的序列,以逗號分隔" clearable @input="inputChange" />
      </el-form-item>
      <el-form-item label="">
        <el-input v-model="form.delValue" placeholder="請輸入從第幾個開始刪" clearable @input="delValueChange" />
      </el-form-item>
      <el-form-item>
        <el-button type="primary" @click="onSubmit">計算</el-button>
      </el-form-item>
      <p v-if="result">剩下的是：{{ result }}</p>
    </el-form>
  </div>
</template>

<script>

var person = []  //存放佇列
var len = 3  //從第幾個開始刪，預設第3個
 

// 替換中文逗號 function ReplaceChina(obj) { while (obj.indexOf('，') !== -1) { obj = obj.replace(/，/ig, ',') } return obj } function LList() { this.head = new Node('head') this.head.next = this.head this.find = find this.insert = insert this.display = display this.findPrevious = findPrevious this.remove = remove } function Node(element) { this.element = element this.next = null } 
//找到當前節點的上一個節點
function findPrevious(item) {
  var currNode = this.head
  while (currNode.next.element !== item) {
    currNode = currNode.next
  }
  return currNode
}
//顯示結果
function display() {
  var currNode = this.head
  const arr = []
  while (currNode.next.element !== 'head') {
    arr.push(currNode.next.element)
    currNode = currNode.next
  }
  return arr
}
//找到當前節點的位置
function find(item) {
  var currNode = this.head
  while (currNode.element !== item) {
    currNode = currNode.next
  }
  return currNode
}
//插入一個節點
function insert(newElement, item) {
  var newNode = new Node(newElement)
  var current = this.find(item)
  newNode.next = current.next
  current.next = newNode
}

function remove(item) {
  var prevNode = this.findPrevious(item) //上一個節點
  let nextDel = prevNode.next //下一個需要刪除的節點
  prevNode.next = prevNode.next.next //刪除item節點（把item上一個節點的指標指向item的下一個節點，即刪除了item)
  let i = 0
  while (i < len) {  //找到第len個的元素，即下次要刪除的節點
    if (nextDel.next.element === 'head') {//如果到了最開頭，則向後移一位，並退出此次迴圈，並不累計i的值
      nextDel = nextDel.next
      continue
    }
    nextDel = nextDel.next 
    i++
  }
  return nextDel  //返回下次要刪除的節點
}

export default {
  name: 'TestActivity',
  data() {
    return {
      form: {
        value: '',
        delValue: ''
      },
      result: '',
      person: []
    }
  },
  mounted() {
  },
  methods: {
    delValueChange(val) {
      len = Number(val)  //格式化為數值型別
    },
    inputChange(val) {
      person = val.split(',')//把字串存入佇列陣列
    },
    onSubmit() {
      if (!this.form.value || !this.form.delValue) {
        this.$alertMessage('error', '請輸入必填項')
        return
      }
      const timesString = ReplaceChina(this.form.value) // 替換中文分號
      person = timesString.split(',')
      if (this.form.delValue > person.length) {
        this.$alertMessage('error', '開始刪除的位置不能大於佇列總數')
        return
      }

      const first = 'head'
      let i = 0
      const cities = new LList()  //例項化一個例項
      // 把person陣列放入cities連結串列
      while (i < person.length) {
        if (i === 0) {
          cities.insert(person[0], first)
        } else {
          const j = i - 1
          cities.insert(person[i], person[j])
        }
        i++
      }
      // 顯示當前排隊情況
      cities.display()
      const length = len - 1
      let delName = person[length] //當前要刪掉的節點
　　　 //迴圈去刪掉節點，留下最後2個
      while (person.length > 2) {
        delName = cities.remove(delName).element
        person = cities.display()
        this.result = person.join(',')//最後的結果
      }
    }
  }
}
</script>
<style  scoped>
.main{
  padding: 20px ;
}
.main >>> .el-input__inner{
   width:
 }
</style>

<style lang="scss" scoped>
</style>