C语言位图及位图的实现

#pragma once
#include<vector>
 
//只能用于整型，节省空间 
class BitSet
{
public:
 BitSet(size_t range)
 {
  //当range为8以下的时候，会开辟0个空间，会出错
  _bitSet.resize(range/8+1,0);
 }
 
 void Set(size_t value)
 {
  size_t index = value / 8;  //value>>3
  size_t pos = value % 8;
 
  _bitSet[index] |= (1<<pos); //置1：或1
 }
 
 void ReSet(size_t value) //重置
 {
  size_t index = value / 8;
  size_t pos = value % 8;
 
  _bitSet[index] &= ~(1<<pos); //置0: 与0
 }
 
 bool Test(size_t value) //检测
 {
  size_t index = value / 8;
  size_t pos = value % 8;
  
  return _bitSet[index] & (1<<pos);
 
 }
 
protected:
 vector<char> _bitSet;
};
 
void TestBitMap()
{
 BitSet b(-1); //-1转为无符号数就是最大值
 b.Set(5);
 b.Set(999);
 b.Set(1022);
 b.Set(111110000);
 
 cout<<b.Test(5)<<endl;
 cout<<b.Test(100)<<endl; //100不在位图当中
 cout<<b.Test(999)<<endl;
 cout<<b.Test(1022)<<endl;
 cout<<b.Test(111110000)<<endl;
}