#include"binary.h"

namespace myLib

{

/**************************************************

* * @file binary.cpp

* * @author EncodedStar

* * @date 2019.7.3

* * @function 计算n二进制的时候存在几个1

***************************************************/

int count_binary(int n) {

int res = 0;

while (n != 0) {

n = n & (n - 1);

res++;

}

return res;

}

/**************************************************

* * @file binary.cpp

* * @author EncodedStar

* * @date 2019.7.5

* * @function 16进制打印

***************************************************/

std::string toHex(int num) {

if (num == 0) return "0";

std::string hex = "0123456789abcdef", ans = "";

while(num && ans.size() < 8){

ans = hex[num & 0xf] + ans;

num >>= 4;

}

return ans;

}

/**************************************************

* * @file binary.cpp

* * @author EncodedStar

* * @date 2019.7.5

* * @function int转化string and vector<string>

***************************************************/

std::string int2String(int n) {

std::stringstream tmpss;

std::string tmps;

tmpss.clear();

tmpss << n;

tmpss >> tmps;

tmpss.str("");

return tmps;

}

vector<string> int2VString(int n) {

vector<string> tmpv;

for(int i = 1; i <= n; i++)

{

tmpv.push_back(int2String(i));

}

return tmpv;

}

/**************************************************

* * @file binary.cpp

* * @author EncodedStar

* * @date 2020.3.23

* * @function 开平方

***************************************************/

float Q_rsqrt( float number )

{

long i;

float x2, y;

const float threehalfs = 1.5F;

x2 = number * 0.5F;

y = number;

i = * ( long * ) &y; // evil floating point bit level hacking

i = 0x5f3759df - ( i >> 1 ); // what the fuck?

y = * ( float * ) &i;

y = y * ( threehalfs - ( x2 * y * y ) ); // 1st iteration

// 2nd iteration, this can be removed

// // y = y * ( threehalfs - ( x2 * y * y ) );

return y;

}

}