package utils

import "strconv"

// Intersect 返回两个数组的交集
func Intersect(nums1 []int64, nums2 []int64) []int64 {
	if len(nums1) > len(nums2) {
		return Intersect(nums2, nums1)
	}
	m := map[int64]int64{}
	for _, num := range nums1 {
		m[num]++
	}

	var intersection []int64
	for _, num := range nums2 {
		if m[num] > 0 {
			intersection = append(intersection, num)
			m[num]--
		}
	}
	return intersection
}

////求交集
//func intersect(slice1, slice2 []int64) []int64 {
//	m := make(map[int64]int)
//	nn := make([]int64, 0)
//	for _, v := range slice1 {
//		m[v]++
//	}
//
//	for _, v := range slice2 {
//		times, _ := m[v]
//		if times == 1 {
//			nn = append(nn, v)
//		}
//	}
//	return nn
//}

// Difference 求差集 slice1-并集
func Difference(slice1, slice2 []int64) []int64 {
	m := make(map[int64]int)
	nn := make([]int64, 0)
	inter := Intersect(slice1, slice2)
	for _, v := range inter {
		m[v]++
	}

	for _, value := range slice1 {
		times, _ := m[value]
		if times == 0 {
			nn = append(nn, value)
		}
	}
	return nn
}

func SliceAtoi(sa []string) ([]int64, error) {
	si := make([]int64, 0, len(sa))
	for _, a := range sa {
		i, err := strconv.ParseInt(a, 10, 64)
		if err != nil {
			return si, err
		}
		si = append(si, i)
	}
	return si, nil
}