vector常用操作

初始化和赋值

// constructing vectors #include 
#include  using namespace std; int main ()
{
  unsigned int i; // constructors used in the same order as described above:  vector<int> first; // empty vector of ints  vector<int> second (4,100); // four ints with value 100  vector<int> third (second.begin(),second.end()); // iterating through second  vector<int> fourth (third); // a copy of third // the iterator constructor can also be used to construct from arrays:  int myints[] = {16,2,77,29};
  vector<int> fifth (myints, myints + sizeof(myints) / sizeof(int) );

  cout << "The contents of fifth are:"; for (i=0; i < fifth.size(); i++)
    cout << " " << fifth[i];

  cout << endl; return 0;
}

 

遍历

// vector::operator[] #include 
#include  using namespace std; int main ()
{
  vector<int> myvector (10); // 10 zero-initialized elements  unsigned int i;

  vector<int>::size_type sz = myvector.size(); // assign some values:  for (i=0; i// reverse vector using operator[]:  for (i=0; i2; i++)
  { int temp;
    temp = myvector[sz-1-i];
    myvector[sz-1-i]=myvector[i];
    myvector[i]=temp;
  }

  cout << "myvector contains:"; for (i=0; i" " << myvector[i];

  cout << endl; return 0;
}

 

追加

// vector::push_back #include 
#include  using namespace std; int main ()
{
  vector<int> myvector; int myint;

  cout << "Please enter some integers (enter 0 to end):\n"; do {
    cin >> myint;
    myvector.push_back (myint);
  } while (myint);

  cout << "myvector stores " << (int) myvector.size() << " numbers.\n"; return 0;
}

 

插入

// inserting into a vector #include 
#include  using namespace std; int main ()
{
  vector<int> myvector (3,100);
  vector<int>::iterator it;

  it = myvector.begin();
  it = myvector.insert ( it , 200 );

  myvector.insert (it,2,300); // "it" no longer valid, get a new one:  it = myvector.begin();

  vector<int> anothervector (2,400);
  myvector.insert (it+2,anothervector.begin(),anothervector.end()); int myarray [] = { 501,502,503 };
  myvector.insert (myvector.begin(), myarray, myarray+3);

  cout << "myvector contains:"; for (it=myvector.begin(); it" " << *it;
  cout << endl; return 0;
}

 

删除

// erasing from vector #include 
#include  using namespace std; int main ()
{
  unsigned int i;
  vectorint> myvector; // set some values (from 1 to 10)  for (i=1; i<=10; i++) myvector.push_back(i); // erase the 6th element  myvector.erase (myvector.begin()+5); // erase the first 3 elements:  myvector.erase (myvector.begin(),myvector.begin()+3);

  cout << "myvector contains:"; for (i=0; i" " << myvector[i];
  cout << endl; return 0;
}

 

清空

// clearing vectors #include 
#include  using namespace std; int main ()
{
  unsigned int i;
  vector<int> myvector;
  myvector.push_back (100);
  myvector.push_back (200);
  myvector.push_back (300);

  cout << "myvector contains:"; for (i=0; i" " << myvector[i];

  myvector.clear();
  myvector.push_back (1101);
  myvector.push_back (2202);

  cout << "\nmyvector contains:"; for (i=0; i" " << myvector[i];

  cout << endl; return 0;
}