vector

Posted 2022-04-18 xpylovely

//4种遍历方法

for (int i = 0; i < v1.size(); i++)
cout << v1[i] << " ";

for (int i = 0; i < v1.size(); i++)
cout << v1.at(i) << " ";

for (vector<int>::reverse_iterator it = v1.rbegin(); it != v1.rend(); it++)
cout << *it << " ";

for (vector<int>::iterator it = v1.begin(); it != v1.end(); it++)
cout << *it << " ";

//4种初始化

vector<int> v2 = v1;

vector<int> v2(v1);

//使用部分元素来构造 vector<int> v3(v1.begin(), v1.begin() + 1);
 vector<int> v4(v1.begin(), v1.end()); 
//存放三个元素，每个元素都是9
 vector<int> v5(3,9);

 vector<int> v5(4);//4个0  未指定初始化的值

.pushback()//尾部插入

.size()//尺寸

.erase(it,end);//删除it和end之间的元素

.erase(it）//删除it

v1.insert(v1.begin(), 10);//首部之前插入10

v1.insert(v1.begin(), 2, 15);//首部之前插入2个15