vector<int> vec;

for(int i = 1; i <= 7; ++i)

vec.push_back(i);

cout << "The capacity = " << vec.capacity() << endl << endl;

// size <= capacity，不需要重新分配

auto itbegin = vec.begin();

auto itend = vec.end();

vec.push_back(8);

auto itbegin_1 = vec.begin();

auto itend_1 = vec.end();

if(itbegin == itbegin_1)

cout << "Begin same." << endl;

else

cout << "Begin different." << endl;

if(itend == itend_1)

cout << "End same." << endl;

else

cout << "End different." << endl;

cout << endl;

// size > capacity,重新分配内存

vec.push_back(9);

auto itbegin_2 = vec.begin();

auto itend_2 = vec.end();

if(itbegin_2 == itbegin_1)

cout << "Begin same." << endl;

else

cout << "Begin different." << endl;

if(itend_2 == itend_1)

cout << "End same" <<endl;

else

cout << "End different." << endl;

cout << endl;

cout << "The size = " << vec.size() << endl;

cout << "The capacity = " << vec.capacity() << endl << endl;

// 删除元素

auto itend_3 = vec.end();

auto itbegin_3 = vec.begin();

for(auto itmove = itbegin_3; itmove != itend_3; ++itmove) {

cout << *itmove << " ";

if(*itmove == 3) {

vec.erase(itmove);

cout << endl << "Now the 3rd number = " << *itmove;

auto itbegin_4 = vec.begin();

auto itend_4 = vec.end();

cout << endl;

if(itbegin_3 == itbegin_4)

cout << "Begin same." << endl;

else

cout << "Begin different." << endl;

if(itend_3 == itend_4)

cout << "End same" <<endl;

else

cout << "End different." << endl;

}

}

cout << endl << endl << "The size = " << vec.size() << endl << endl;

// 正确删除方式

for(auto itmove = vec.begin(); itmove != vec.end();) {

cout << *itmove << " ";

if(*itmove == 4) {

itmove = vec.erase(itmove);

cout << endl << "The next effect = " << *itmove << endl;

}

else

++itmove;

}

return 0;

}