GO语言bit集合

GO语言bit集合相关操作

package main

import(
    "fmt"
    "bytes"
)

type IntSet struct {
    words []int64
}

func (s *IntSet) Add(n int) {
    word, bit := n / 64, uint(n % 64)
    for word >= len(s.words) {
        s.words = append(s.words, 0)
    }
    s.words[word] |= 1 << bit
}

func (s *IntSet) Has(n int) bool {
    word, bit := n / 64, uint(n % n)
    return word < len(s.words) && s.words[word] & (1 << bit) != 0
}

func (s *IntSet) Remove(n int) bool {
    has := s.Has(n)
    if !has {
        return false
    }
    word, bit := n / 64, uint(n % 64)
    s.words[word] = s.words[word] - (1 << bit)
    return true
}

func (s *IntSet) UnionSet(t *IntSet) {
    for key, val := range t.words {
        if key < len(s.words) {
            s.words[key] |= val
        } else {
            s.words = append(s.words, val)
        }
    }
}

func (s *IntSet) String() string {
    var buf bytes.Buffer
    buf.WriteByte("{")
    for key, val := range s.words {
       if val == 0 {
            continue
       }
       for i := 0; i < 64; i++ {
            if val & (1 << uint(i)) != 0 {
                if buf.Len() > len("{") {
                    buf.WriteByte(",")
                }
                fmt.Fprintf(&buf, "%d", 64*key+i)
            }
       }
    }
    buf.WriteByte("}")
    return buf.String()
}

func (s *IntSet) Len() int {
    var num int = 0
    for _, word := range s.words {
        for i := 0; i < 64; i++ {
            if word & (1 << uint(i)) != 0 {
                num++
            }
        }
    }
    return num
}

func (s *IntSet) Clear() {
    s.words = s.words[:0]
}

func (s *IntSet) Copy() *IntSet {
    var t *IntSet = new(IntSet)
    for _, word := range s.words {
        t.words = append(t.words, word)
    }
    return t
}