[OI] C ++ STL vector variable length arrays

Vector vector originally meaning, but in the use of a similar length of the array is not limited.

Definition Syntax: Vector <data type> name;

First, the header file: <vector> (bits / stdc ++ please ignore)

Second, the commonly used methods:

  a.size (); // read size

  a.resize (): // resize

  a.push_back (); // add elements to the tail

  a.pop_back (); // remove the last element

  a.clear (); // Clear

  a.empty (): // returned is empty

Third, traversal

  STL data type is almost (perhaps all) using an iterator to traverse.

  vector <int> :: = a.begin IT Iterator ();  // create a vector iterator type (similar pointer) pointing to a first address

  Write for in that:

  for (vector<int>::iterator it = a.begin(); it != a.end();it++)

  * It can then be used to access the value of the address pointed.

Fourth, other

  Insert elements: vec.insert (vec.begin () + i , a); a is inserted in front of the first element i + 1; (i.e. this is the location a i + 1) is
  deleted elements: vec.erase (vec .begin () + 2); remove the third element
  vec.erase (vec.begin () + i, vec.end () + j); delete interval [i, j-1]; interval from 0   (the controversy is relatively large, retained doubts, not normal)

To be added…………

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Origin www.cnblogs.com/nowonder/p/STL_VECTOR.html