mirror of
https://github.com/golang/go
synced 2024-09-05 16:04:50 +00:00
129 lines
2.7 KiB
Go
129 lines
2.7 KiB
Go
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// Copyright 2021 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package a
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// SliceEqual reports whether two slices are equal: the same length and all
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// elements equal. All floating point NaNs are considered equal.
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func SliceEqual[Elem comparable](s1, s2 []Elem) bool {
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if len(s1) != len(s2) {
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return false
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}
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for i, v1 := range s1 {
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v2 := s2[i]
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if v1 != v2 {
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isNaN := func(f Elem) bool { return f != f }
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if !isNaN(v1) || !isNaN(v2) {
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return false
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}
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}
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}
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return true
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}
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// A Set is a set of elements of some type.
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type Set[Elem comparable] struct {
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m map[Elem]struct{}
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}
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// Make makes a new set.
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func Make[Elem comparable]() Set[Elem] {
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return Set[Elem]{m: make(map[Elem]struct{})}
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}
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// Add adds an element to a set.
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func (s Set[Elem]) Add(v Elem) {
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s.m[v] = struct{}{}
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}
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// Delete removes an element from a set. If the element is not present
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// in the set, this does nothing.
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func (s Set[Elem]) Delete(v Elem) {
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delete(s.m, v)
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}
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// Contains reports whether v is in the set.
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func (s Set[Elem]) Contains(v Elem) bool {
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_, ok := s.m[v]
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return ok
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}
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// Len returns the number of elements in the set.
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func (s Set[Elem]) Len() int {
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return len(s.m)
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}
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// Values returns the values in the set.
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// The values will be in an indeterminate order.
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func (s Set[Elem]) Values() []Elem {
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r := make([]Elem, 0, len(s.m))
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for v := range s.m {
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r = append(r, v)
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}
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return r
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}
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// Equal reports whether two sets contain the same elements.
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func Equal[Elem comparable](s1, s2 Set[Elem]) bool {
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if len(s1.m) != len(s2.m) {
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return false
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}
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for v1 := range s1.m {
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if !s2.Contains(v1) {
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return false
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}
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}
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return true
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}
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// Copy returns a copy of s.
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func (s Set[Elem]) Copy() Set[Elem] {
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r := Set[Elem]{m: make(map[Elem]struct{}, len(s.m))}
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for v := range s.m {
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r.m[v] = struct{}{}
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}
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return r
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}
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// AddSet adds all the elements of s2 to s.
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func (s Set[Elem]) AddSet(s2 Set[Elem]) {
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for v := range s2.m {
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s.m[v] = struct{}{}
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}
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}
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// SubSet removes all elements in s2 from s.
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// Values in s2 that are not in s are ignored.
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func (s Set[Elem]) SubSet(s2 Set[Elem]) {
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for v := range s2.m {
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delete(s.m, v)
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}
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}
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// Intersect removes all elements from s that are not present in s2.
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// Values in s2 that are not in s are ignored.
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func (s Set[Elem]) Intersect(s2 Set[Elem]) {
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for v := range s.m {
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if !s2.Contains(v) {
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delete(s.m, v)
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}
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}
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}
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// Iterate calls f on every element in the set.
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func (s Set[Elem]) Iterate(f func(Elem)) {
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for v := range s.m {
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f(v)
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}
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}
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// Filter deletes any elements from s for which f returns false.
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func (s Set[Elem]) Filter(f func(Elem) bool) {
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for v := range s.m {
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if !f(v) {
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delete(s.m, v)
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}
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}
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}
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