LeetCode-341

题目

341. 扁平化嵌套列表迭代器

结果

代码

/**
 * // This is the interface that allows for creating nested lists.
 * // You should not implement it, or speculate about its implementation
 * type NestedInteger struct {
 * }
 *
 * // Return true if this NestedInteger holds a single integer, rather than a nested list.
 * func (this NestedInteger) IsInteger() bool {}
 *
 * // Return the single integer that this NestedInteger holds, if it holds a single integer
 * // The result is undefined if this NestedInteger holds a nested list
 * // So before calling this method, you should have a check
 * func (this NestedInteger) GetInteger() int {}
 *
 * // Set this NestedInteger to hold a single integer.
 * func (n *NestedInteger) SetInteger(value int) {}
 *
 * // Set this NestedInteger to hold a nested list and adds a nested integer to it.
 * func (this *NestedInteger) Add(elem NestedInteger) {}
 *
 * // Return the nested list that this NestedInteger holds, if it holds a nested list
 * // The list length is zero if this NestedInteger holds a single integer
 * // You can access NestedInteger's List element directly if you want to modify it
 * func (this NestedInteger) GetList() []*NestedInteger {}
 */
 
type NestedIterator struct {
	nums  []int
	index int
}

func Constructor(nestedList []*NestedInteger) *NestedIterator {
	var itr NestedIterator
	for _, v := range nestedList {
		itr.nums = append(itr.nums, getNums(v)...)
	}
	return &itr
}

func getNums(integer *NestedInteger) (nums []int) {
	if integer.IsInteger() {
		nums = append(nums, integer.GetInteger())
	} else {
		for _, v := range integer.GetList() {
			nums = append(nums, getNums(v)...)
		}
	}
	return nums
}

func (this *NestedIterator) Next() int {
	this.index++
	return this.nums[this.index-1]
}

func (this *NestedIterator) HasNext() bool {
	if this.index == len(this.nums) {
		return false
	}
	return true
}