学步园

参考于http://www.sjsjw.com/kf_code/article/86_31843_24280.asp

#include<iostream>
using namespace std;

class BitOperation{
public:
	int getMaxInt(){  //获得Int型最大值
		return ((unsigned int)-1)/2;
		//return (1<<31)-1;
		//return ~(1<<31);
	}//getMaxInt

	int getMinInt(){   //获得Int型最小值
		return 1<<31;
	}//getMinInt

	long getMaxLong(){  //获得Long型最大值
		return ((unsigned long)-1)/2;//2147483648
	//Java	return ((long)1<<127)-1;     922337203685477
	}//getMaxLong

	int mulTwo(int n){  //n*2
		return n<<1;
	}//mulTwo

	int divTwo(int n){   //n/2
		return n>>1;
	}//divTwo

	int mulTwoPower(int n,int m){   //n*2^m
		return n<<m;
	}//mulTwoPower

	int divTwoPower(int n,int m){   //n/2^m
		return n>>m;
	}//divTwoPower

	bool isOddNumber(int n){   //判断一个数的奇偶性
		return (n&1)==1;
	}//isOddNumber

	void swap(int *a,int *b){  //交换两个数
	//	a^=b;b^=a;a^=b;
		   (*a)^=(*b)^=(*a)^=(*b);
	}//swap

	int abs(int n){     //取绝对值
		return (n^(n>>31))-(n>>31);
		//return n>0?n:-n;
	}//abs

	int max(int a,int b){   //获得两个数中的最大值
		return a^((a^b) & -(a<b));
		//return b&((a-b)>>31) | a&(~(a-b)>>31);
		//return (a+b+abs(a-b))/2;
		//return a>b?a:b;
	}//max

	int min(int a,int b){   //获得两个数中的最小值
        //return a>b?b:a;
		//return (a+b-abs(a-b))/2;
		//return a&((a-b)>>31) | b&(~(a-b)>>31);
		return a^((a^b) & -(a>b));
	}//min

	int isSameSign(int x,int y){  //判断两个数字是否同号，同号返回1,异号返回0
		return (x^y)>-1;
	}//isSameSign

	int pow2(int n){   //2^n
		return 2<<(n-1);
	}//pow2

	int isFactorialofTwo(int n){   //判断一个数是不是2的幂
		return (n&(n-1))==0;
	}//isFactorialofTwo

	int quyu(int m,int n){     //对n^2取余
		return m&(n-1);
	}//quyu

	int getAverage(int x,int y){  //求两个数的平方数
		return ((x^y)>>1)+(x&y);
	}//getAverage

	int getBit(int n,int m){    //低位到高位，取n的第m位
		return (n>>(m-1))&1;
	}//getBit

	int setBitToOne(int n,int m){  //低位到高位，将n的第m位置置1
		return n|(1<<(m-1));
	}//setBitToOne

	int setBitToZero(int n,int m){//低位到高位，将n的第m位置0
		return n&(0<<(m-1));
	}//setBitToZero

	int addOne(int n){  //n+1
		return -~n;
	}//addOne

	int minusOne(int n){  //n-1
		return ~-n;
	}//minusOne

	int OppositeNumber(int n){  //取相反数
		return ~n+1;
	}//OppositeNumber

	int sign(int n){  //正数为1，零为0，负数为-1
		return !!n-(((unsigned)n>>31)<<1);
	}//sign
};

int main(){
	BitOperation BO;
	cout<<"BO.getMaxInt() "<<BO.getMaxInt()<<endl;
	cout<<"BO.getMinInt() "<<BO.getMinInt()<<endl;
	cout<<"BO.getMaxLong() "<<BO.getMaxLong()<<endl;

	cout<<"BO.mulTwo(2) "<<BO.mulTwo(2)<<endl;
	cout<<"BO.divTwo(2) "<<BO.divTwo(2)<<endl;

	cout<<"BO.mulTwoPower(1024,2) "<<BO.mulTwoPower(1024,2)<<endl;
	cout<<"BO.divTwoPower(1024,2) "<<BO.divTwoPower(1024,2)<<endl;

	cout<<"BO.isOddNumber(3) "<<BO.isOddNumber(3)<<endl;
	cout<<"BO.isOddNumber(4) "<<BO.isOddNumber(4)<<endl;

	cout<<"BO.swap(&a,&b)"<<endl;
	int a=2,b=3;
	cout<<a<<" "<<b<<endl;
	BO.swap(&a,&b);
	cout<<a<<" "<<b<<endl;

	cout<<"BO.abs(-1) "<<BO.abs(-1)<<endl;
	cout<<"BO.abs(1) "<<BO.abs(1)<<endl;

	cout<<"BO.max(100,1) "<<BO.max(100,1)<<endl;
	cout<<"BO.min(100,1) "<<BO.min(100,1)<<endl;

	cout<<"BO.isSameSign(-1,-1) "<<BO.isSameSign(-1,-1)<<endl;
	cout<<"BO.isSameSign(-1,1) "<<BO.isSameSign(-1,1)<<endl;

	cout<<"BO.pow2(2) "<<BO.pow2(2)<<endl;

	cout<<"BO.isFactorialofTwo(1024) "<<BO.isFactorialofTwo(1024)<<endl;
	cout<<"BO.isFactorialofTwo(1023) "<<BO.isFactorialofTwo(1023)<<endl;

	cout<<"BO.quyu(20,10) "<<BO.quyu(20,10)<<endl;

	cout<<"BO.getAverage(10,20) "<<BO.getAverage(10,20)<<endl;

	//0000 0000 0000 0000 0000 0000 0000 0001  (1)
	//0000 0000 0000 0000 0000 0000 0000 0011  (3)
	cout<<"BO.setBitToOne(1,2) "<<BO.setBitToOne(1,2)<<endl;
	//0000 0000 0000 0000 0000 0000 0000 0000  (0)
	cout<<"BO.setBitToZero(1,1) "<<BO.setBitToZero(3,1)<<endl;

	cout<<"BO.addOne(1) "<<BO.addOne(1)<<endl;
	cout<<"BO.minusOne(1) "<<BO.minusOne(1)<<endl;

	cout<<"BO.OppositeNumber(1) "<<BO.OppositeNumber(1)<<endl;
	cout<<"BO.OppositeNumber(-1) "<<BO.OppositeNumber(-1)<<endl;

	cout<<"BO.sign(200) "<<BO.sign(200)<<endl;
	cout<<"BO.sign(0) "<<BO.sign(0)<<endl;
	cout<<"BO.sign(-200) "<<BO.sign(-200)<<endl;
	return 0;
}