package common

// Data. Predict: ["4"]
// a := []string{"1","2","3","4"}
// b := []string{"0","1","2","3"}
func GetASliceInt32NotInB(a []int32, b []int32) []int32 {
	var c []int32
	temp := map[int32]struct{}{}
	for _, val := range b {
		if _, ok := temp[val]; !ok {
			temp[val] = struct{}{} // 空struct 不占内存空间
		}
	}

	for _, val := range a {
		if _, ok := temp[val]; !ok {
			c = append(c, val)
		}
	}

	return c
}