vector常用操作

初始化和赋值

// constructing vectors
#include <iostream>
#include <vector>
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 <iostream>
#include <vector>
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<sz; i++) myvector[i]=i;

  // reverse vector using operator[]:
  for (i=0; i<sz/2; i++)
  {
    int temp;
    temp = myvector[sz-1-i];
    myvector[sz-1-i]=myvector[i];
    myvector[i]=temp;
  }

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

  cout << endl;

  return 0;
}

 

追加

// vector::push_back
#include <iostream>
#include <vector>
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 <iostream>
#include <vector>
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  // "it" no longer valid, get a new one: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<myvector.end(); it++)
    cout << " " << *it;
  cout << endl;

  return 0;
}

 

删除

// erasing from vector
#include <iostream>
#include <vector>
using namespace std;

int main ()
{
  unsigned int i;
  vector<unsigned int> 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.size(); i++)
    cout << " " << myvector[i];
  cout << endl;

  return 0;
}

 

清空

// clearing vectors
#include <iostream>
#include <vector>
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.size(); i++) cout << " " << myvector[i];

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

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

  cout << endl;

  return 0;
}

 

更多操作

    参考 http://www.cplusplus.com/reference/stl/vector/