C + + STL vector detailed

A. explanation:

Vector: is a sequential container, in fact the same as the array, but it is superior to arrays. In general, arrays cannot be expanded dynamically, so it is not a waste of memory when the program is running, which is causing cross-border. and Vector just makes up for this flaw, it is characterized by the equivalent of a scalable array, its random access fast, in the middle of insertions and deletions slow, but at the end of insertions and deletions Fast.

Two. usage:

1. Header Files

2. How to define

A) vector<int>v1; // vector elements are of type  int B) vector<string>v2; // vector element is of type  string C) vector<node>v3; // the queue element is a structural body, and the structure can be defined by itself

Vector<int>::iterator it; //define an iterator

3. Common operation

V1.push_back ()//add a data at the end of the arrayV1.pop_back ()//remove the last data from the array
V1.front () //return first element (top element of Stack)V1.begin ()//gets the pointer to the array header, which is accepted by the iteratorV1.end ()//get a pointer to the last cell +1 of the array, using an iterator to acceptV1.clear ()//Remove all data from the containerV1.empty ()//determine if the container is emptyV1.erase (POS)//Delete Data at the POS locationV1.erase (beg,end)//Delete data from the [beg,end] intervalV1.size ()//the number of actual data in the back container
V1.insert (pos,data)//insert data at POS

Three. Example

#include <iostream>#include<algorithm>#include<vector>using namespacestd;intmain () {vector<int> v;//Defining Vectorsvector<int>::iterator it;//define a vector iterator     for(inti =Ten; I >=1; I--)//Inserting DataV.push_back (i); cout<<"output:";  for(it=v.begin (); it!=v.end (); it++)//the value of the output iteratorcout<<*it<<" "; cout<<endl; It-=1; cout<<"the last value is:"<<*it<<"     "<<endl;                             V.erase (it); //Delete last elementcout <<"Number of Elements:"<<v.size () << endl;//number of output elementsSort (v.begin (), v.end ());//Vector Sortcout<<"after Sorting:";  for(it=v.begin (); it!=v.end (); it++)//Output vector elementscout << *it <<" "; cout<<endl; V.insert (v.begin (), -) ;//inserting a elem at the POS locationcout<<"the first element is:"<<v.front () <<endl;//outputs the first elementV.pop_back ();//remove the last elementcout <<"Number of Elements:"<<v.size () << endl;//number of output elementsV.clear ();//Vector Emptycout <<"number of elements after emptying:"<< v.size () << endl;//number of output elements    return 0;}

C + + STL vector detailed