数据结构设计

package main

import (
    "fmt"
)

type BitMap struct {
    bits []byte
}

func NewBitMap(capacity int) BitMap {
    return BitMap{make([]byte, (capacity+7)/8)}
}

func (bitmap *BitMap) Set(num int) {
    if (num > 8*len(bitmap.bits)) {
        return
    }
    pos := num / 8
    offset := uint(num % 8)
    bitmap.bits[pos] |= (0x80 >> offset)
}

func (bitmap *BitMap) Check(num int) bool {
    if (num > 8*len(bitmap.bits)) {
        return false
    }
    pos := num / 8
    offset := uint(num % 8)
    return bitmap.bits[pos] & (0x80 >> offset) > 0
}

func main() {
    bitmap := NewBitMap(15)
    bitmap.Set(2)
    bitmap.Set(15)
    bitmap.Set(30)
    fmt.Println(bitmap.Check(2))
    fmt.Println(bitmap.Check(3))
    fmt.Println(bitmap.Check(15))
    fmt.Println(bitmap.Check(30))
}