go - 如何找到两个字符串 slice 之间的差异

Question

这是我想要的结果

slice1 := []string{"foo", "bar","hello"}
slice2 := []string{"foo", "bar"}

difference(slice1, slice2)
=> ["hello"]

我正在寻找两个字符串 slice 之间的区别!

Answer 1

假设 Go map 是 ~O(1)，这是一个适用于未排序 slice 的 ~O(n) 差分函数。

// difference returns the elements in `a` that aren't in `b`.
func difference(a, b []string) []string {
    mb := make(map[string]struct{}, len(b))
    for _, x := range b {
        mb[x] = struct{}{}
    }
    var diff []string
    for _, x := range a {
        if _, found := mb[x]; !found {
            diff = append(diff, x)
        }
    }
    return diff
}