16. BitMap算法

位图

#include<iostream>
#include<vector>
using namespace std;
class BitMap{
public:
    BitMap(size_t range){
        _bits.resize(range/32+1);
    }
    void set(size_t x){
        int index=x>>5;
        int position=x&0x31;
        _bits[index]|=(1<<position);
    }
    void reset(size_t x){
        int index=x>>5;
        int position=x&0x31;
        _bits[index]&=~(1<<position);
    }
    bool isExist(size_t x){
        int index=x>>5;
        int position=x&0x31;
        return (_bits[index]&(1<<position))!=0;
    }
private:
    vector<int> _bits;
};
void test(){
    BitMap bm(200);
    bm.set(136);
    bm.set(1);
    cout<<bm.isExist(136)<<endl;
    bm.reset(136);
    cout<<bm.isExist(136)<<endl;
}
int main(){
    test();
    system("pause");
    return 0;
}