【C/C++学院】0829-位容器multimapmutisetString/算法函数兰不达表达式以及类重载/GPU编程

位容器multimapmutisetString

Multiset

#include <set>
#include <iostream>

using namespace std;

void mainA()
{
multiset<int> myset;
myset.insert(100);
myset.insert(101);
myset.insert(100);
myset.insert(103);
myset.insert(100);

auto pfind = myset.find(101);
std::cout << *pfind << std::endl;

auto allfind = myset.equal_range(100);
//找到红黑树的链表节点，遍历所有的元素

//find链表的头结点，second最后一个空节点，遍历所有的元素
for (auto it = allfind.first; it != allfind.second;it++)
{
cout << *it << endl;
}

cin.get();
}

Multimap

#include <iostream>
#include <map>
#include <string>

using namespace std;

void main2()
{
multimap<string, string> mymap;
mymap.insert(pair<string, string>("yincheng", "a"));
mymap.insert(pair<string, string>("yincheng1", "b"));
mymap.insert(pair<string, string>("yincheng", "c"));
mymap.insert(pair<string, string>("yincheng", "d"));

auto ib = mymap.begin();
auto ie = mymap.end();
for (;ib!=ie;ib++)
{
cout << (*ib).first << "   "<<(*ib).second << endl;
}

auto pfind = mymap.find("yincheng");
cout << "\n\n\n";
cout << (*pfind).first << "   " << (*pfind).second<< endl;
cout << "\n\n\n";
auto it = mymap.equal_range("yincheng");//从树节点吧关键字相同的链表全部拔下

//first起点，，secondl链表最后的节点后面一个空节点，都是迭代器
for (auto i = it.first; i != it.second;i++)
{
cout << (*i).first << "   " << (*i).second << endl;
}

cin.get();
cin.get();
}

Bitset

#include <set>
#include <bitset>
#include <iostream>
#include<string>

using namespace std;

void main3X()
{
//8 位， （215）代表构造的数据
bitset<8>bs(215);
for (int i = 0; i < 8;i++)//最高位存储i=7上
{
cout << bs[i];
}

cin.get();
cin.get();
}

void main3Y()
{
//8 位， （215）代表构造的数据
bitset<8>bs(215);
for (int i = 7; i >=0; i--)
{
cout << bs[i] << "  " << ~bs[i] << endl;
}

cin.get();
cin.get();
}

void  main3Z()
{
float num = 1231231236.8;
bitset<32> myset(num);
for (int i = 31; i >=0;i--)
{
cout << myset[i];
}

cin.get();
}

void  main3S()
{
int  num =-5;
bitset<32> myset(num);
for (int i = 31; i >= 0; i--)
{
cout << myset[i];
}
string str = myset.to_string();
cout <<"\n" <<str << endl;

unsigned int data;
data = myset.to_ulong();//补码
cout << "\n" << data<< endl;

cin.get();
}

void main345()
{
bitset<8>bs(255);
bs.set(7, 0);//操作二进制位
bs.set(0, 0);
cout << bs.size() << endl;//位数
//bs.reset();//全部清零
//bs.none();//测试下是否有越位
for (int i = 7; i >=0; i--)//最高位存储i=7上
{
cout << bs[i];
}

cin.get();
}

String容器

#include<string>
#include <iostream>
#include <stdlib.h>

using namespace std;
//字符串初始化
void main1s()
{
char str[124] = "china is  big";
//str = "12321";C写法

//string str1(str);
//str1 = "china  is great";
string str1("ABCDEFG");
str1 = "china  is  china";
std::cout << str1;

cin.get();
}

void main2s()
{
string str1("ABCD");
string str2("1234");
string str3 = str1 + str2;
std::cout << str3;

char stra[12]="1231";
char strb[24]="2132";
//char strc[36] = stra + strb;
cin.get();
}

void main3s()
{
string str1("ABCD");
string str2("1234");
str1.append(str2);
str1 += str2;//字符串的增加
std::cout << str1;

cin.get();
}

void main4s()
{
string str1("ABCD");
string str2("1234");
//任意位置插入字符
str1.insert(str1.begin(),'X');
str1.insert(str1.end(), 'X');
str1.insert(str1.begin()+3,3, 'X');

std::cout << str1;

cin.get();
}

void  main5s()
{
string str1("12345678");
auto ib = str1.begin();
auto ie = str1.end();
for (;ib!=ie;ib++)
{
cout << *ib << endl;
}
//str1.erase(str1.begin());//删除一个字符
//str1.erase(str1.begin()+3,str1.end()-2);//删除某个字符串
str1.erase(3, 4);//c从第三个字符开始删除四个字符
cout << str1 << endl;

cin.get();
}

void main6s()
{
string str1("12345678china");
str1.replace(5, 3, "china");//从0到第三个字符替换为china
//replace,1位置，长度，字符串

cout << str1 << endl;

cin.get();
}

void mainA1()
{
string str("233锄禾日当午,谭胜把地雷买下土,谭胜来跳舞，炸成250");
//cout << (int)str.find("谭胜大爷") << endl;
//int pos = str.find(",");//找到第一个皮配的，不匹配返回-1，
//int pos = str.rfind("谭胜");//找到第一个皮配的，不匹配返回-1，
//int pos = str.find("谭胜");

cin.get();
}

void mainA2()
{
string str("ab123mn");
//int pos = str.find_first_of("123");
//find_firstof是第一个找到与字符串皮配字符位置
//int pos = str.find_first_not_of("abc");
//find_firstof是第一个找到与字符串不皮配字符位置

//int pos = str.find_last_of("123");
//find_firstof是最后一个找到与字符串皮配字符位置
int pos = str.find_last_not_of("123");

cout << pos << endl;

cin.get();
}

void main1234()
{
string str1 = "calc";
string str2 = "ABC1";
char strA[5] = "Asd";
char strB[5] = "Asd";
cout <<( str1 == str2) << endl;//重载了运算符
cout << (strA == strB) << endl;//比较地址

cout << str1.empty()<<endl;////是否为空
const char *p = str1.c_str();
system(p);

cin.get();
}

void main()
{
//谭胜 是 流氓
string str("abc is abc  china is china");
//int pos = str.find('a', 0);//字符也一样
//std::cout << pos << endl;
//pos = str.find('a', pos+1);
//std::cout << pos << endl;
int pos = str.find("abc", 0);//find从指定位置查找

std::cout << pos << endl;
pos = str.find("abc", pos+3);
std::cout << pos << endl;

cin.get();
}

算法函数兰不达表达式以及类重载

#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>

using namespace std;

template<class T>  //模板类，实现对于某些容器元素的操作
class add
{
public:
void operator()( T &t)//重载（）运算符，进行操作
{
t *= 2;
std::cout << t<<"\n";
}
};

void  go(int a)
{
a *= 2;
std::cout << a << "\n";
}

void main()
{
vector<int> myv;
myv.push_back(10);
myv.push_back(9);
myv.push_back(7);
myv.push_back(9);

add<int> addA;//省略，
//for_each(myv.begin(), myv.end(), addA);
//for_each(myv.begin(), myv.end(), add<int>());
//for_each(myv.begin(), myv.end(), go);

auto fun = [](int a, int b){ return a + b; };//Lanmba表达式

auto funA = [](int a){a *= 2; cout << a << endl; };
cout << fun(1, 2) << endl;
for_each(myv.begin(), myv.end(), funA);
for_each(myv.begin(), myv.end(), [](int a){a *= 2; cout << a << endl; });

cin.get();
}

GPU编程

比特币挖矿，经常使用gpu进行计算。

Helloworld

//win7 无法对gpu进行直接的调试
#include <amp.h>//gpu计算
#include <iostream>

using namespace concurrency;
using namespace std;

void main()
{
int a[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
array_view<int> av(10,a);//GPU计算结构，av存储到GPU显存，根据数组初始化

//=直接操作AV，（index<1>idx）操作每一个元素
//extent每一个元素					//restrict (amp) 定位GPU执行
parallel_for_each(av.extent, [=](index<1>idx) restrict (amp)
{

av[idx] += 123;
});

for (int i = 0; i < 10;i++)
{
std::cout << av[i] << endl;

}

cin.get();
}

Gpu调试，需要进行如下的设置



单点测试

#include <iostream>
#include <amp.h>
#include <WinBase.h>//操作系统的底层文件，测试时间

#define COUNT 100000

float nickName_GPU[COUNT];
float nickName_CPU[COUNT];

double rungpu(int num)		 restrict(amp)//限定了只能在GPU内部执行
{
double temp = 0;
for (int i = 0; i < num; i++)
{
temp += i;
}

return temp;

}
double runcpu(int num)		 restrict(cpu)	 //只能在CPU内部执行
{
double temp = 0;
for (int i = 0; i < num; i++)
{
temp += i;
}
return temp;

}
double runcpugpu(int num)		 restrict(amp, cpu)//并发执行
{
double temp = 0;
for (int i = 0; i < num; i++)
{
temp += i;
}
return temp;

}

int main()
{
LARGE_INTEGER freq;
LARGE_INTEGER strt;
LARGE_INTEGER ed;//统计时间， 可以精确到毫秒
QueryPerformanceFrequency(&freq);
QueryPerformanceCounter(&strt);//查询时间

double dx[1] = { 0.0 };//数据， 一个元素的数组
double  db = 0.0;

concurrency::array_view<double> myview(1, dx);//转到gpu进行计算
parallel_for_each(myview.extent,
[=](concurrency::index<1> idx) restrict(amp)
{
myview[idx] += rungpu(20000000);
});

myview.synchronize();//显式等待GPU计算完成并将数据打回内存
printf("%f\n", dx[0]);

QueryPerformanceCounter(&ed);//把每一毫秒全到精确的显示出来
printf("GPU耗时: %d 毫秒\r\n", (ed.QuadPart - strt.QuadPart) * 1000 / freq.QuadPart);
QueryPerformanceCounter(&strt);

printf("%f\n", runcpu(20000000));

QueryPerformanceCounter(&ed);
printf("CPU耗时: %d 毫秒\r\n", (ed.QuadPart - strt.QuadPart) * 1000 / freq.QuadPart);
puts("测试结束");

getchar();
return 0;
}

int mainW(void)//测试并行计算
{
LARGE_INTEGER freq;
LARGE_INTEGER strt;
LARGE_INTEGER ed;
QueryPerformanceFrequency(&freq);
QueryPerformanceCounter(&strt);

concurrency::array_view<float> myView(COUNT, nickName_GPU); //将数据打入显存  ，100000个元素的数组

concurrency::parallel_for_each(myView.extent, [=](concurrency::index<1> idx) restrict(amp)
{
for (int i = 0; i < COUNT/10; i++)
{
myView[idx] = (myView[idx] + 0.1f) / 2.3f;
}
});

myView.synchronize();//显式等待GPU计算完成并将数据打回内存

QueryPerformanceCounter(&ed);
printf("GPU耗时: %d 毫秒\r\n", (ed.QuadPart - strt.QuadPart) * 1000 / freq.QuadPart);
QueryPerformanceCounter(&strt);

for (int idx = 0; idx < COUNT; idx++)
{
for (int i = 0; i < COUNT/10; i++)
{
nickName_CPU[idx] = (nickName_CPU[idx] + 0.1f) / 2.3f;
}
}
QueryPerformanceCounter(&ed);
printf("CPU耗时: %d 毫秒\r\n", (ed.QuadPart - strt.QuadPart) * 1000 / freq.QuadPart);

for (int idx = 0; idx < COUNT; idx++)
{
if (nickName_CPU[idx] != nickName_GPU[idx])
{
puts("CPU和GPU的计算结果不相符！");
getchar();
return 0;
}
}
puts("测试结束");

getchar();
return 0;
}

Cpu的频率快与gpu，适合于单点计算，但是gpu的容器比较多，适合并行计算。

Cpu优势在于单点计算。围绕一个计算器，只计算一个数，计算速度最快。

Gpu优势：并发计算。Gpu加速程序，