69 lines
1.6 KiB
Go
Executable File
69 lines
1.6 KiB
Go
Executable File
// CookieJar - A contestant's algorithm toolbox
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// Copyright (c) 2013 Peter Szilagyi. All rights reserved.
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//
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// CookieJar is dual licensed: use of this source code is governed by a BSD
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// license that can be found in the LICENSE file. Alternatively, the CookieJar
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// toolbox may be used in accordance with the terms and conditions contained
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// in a signed written agreement between you and the author(s).
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// Package bag implements a multi-set data structure supporting arbitrary types
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// (even a mixture).
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//
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// Internally it uses a simple map assigning counts to the different values
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// present in the bag.
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package bag
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// Bag data structure (multiset).
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type Bag struct {
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size int
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data map[interface{}]int
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}
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// Creates a new empty bag.
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func New() *Bag {
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return &Bag{0, make(map[interface{}]int)}
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}
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// Inserts an element into the bag.
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func (b *Bag) Insert(val interface{}) {
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b.data[val]++
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b.size++
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}
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// Removes an element from the bag. If none was present, nothing is done.
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func (b *Bag) Remove(val interface{}) {
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old, ok := b.data[val]
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if ok {
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if old > 1 {
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b.data[val] = old - 1
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} else {
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delete(b.data, val)
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}
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b.size--
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}
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}
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// Returns the total number of elemens in the bag.
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func (b *Bag) Size() int {
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return b.size
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}
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// Counts the number of occurances of an element in the bag.
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func (b *Bag) Count(val interface{}) int {
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return b.data[val]
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}
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// Executes a function for every element in the bag.
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func (b *Bag) Do(f func(interface{})) {
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for val, cnt := range b.data {
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for ; cnt > 0; cnt-- {
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f(val)
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}
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}
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}
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// Clears the contents of a bag.
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func (b *Bag) Reset() {
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*b = *New()
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}
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