Java程序员学习C++之Vector

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

typedef vector<int> MyVector;

int main()
{
//std::vector<int> c;
MyVector c;
c.reserve(40);//初始预留一定的空间，减少分配新空间->复制->删除旧空间的效率消耗
//MyVector c(40,1);//预留一定的空间，并且赋初始值

c.capacity();//容量

for (int i = 0; i < 10;i++)
{
c.push_back(i);
}
/* c.size()返回无符号的int，会提示类型不匹配(“<”: 有符号/无符号不匹配)
for (int i = 0; i < c.size();i++)
{
cout << "c[" << i << "]=" << c[i] << endl;
}
*/

for (MyVector::size_type i = 0; i < c.size(); i++)
{
cout << "c[" << i << "]=" << c[i] << endl;
}

cout << "========================"<< endl;

//迭代器的方式
for (MyVector::iterator itr = c.begin(); itr != c.end();++itr)
{
//distance计算两者偏移
cout << "c[" << distance(c.begin(),itr) << "]=" << *itr << endl;
}

//乱序
random_shuffle(c.begin(), c.end());
for (MyVector::size_type i = 0; i < c.size(); i++)
{
cout << c[i]<<" ";
}
cout << endl;

random_shuffle(c.begin()+3, c.end());

for (MyVector::size_type i = 0; i < c.size(); i++)
{
cout << c[i] << " ";
}
cout << endl;
return 0;
}