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STL tips

admin 11月 13, 2020 0

1. vector

vector template contains functions like push_back(), pop_back(), size(), begin(), end(), front(), back().

First we define a vector:

$ vector<T> vec;

Add or delete element:

$ vec.push_back(1);
$ vec.push_back(3);
$ vec.push_back(5);
$ vec.push_back(1);
$ vec.pop_back();

Define iterator

$ vector<int>::iterator;

Traversal

$ vector<int> vec;
$ vector<int>::iterator itor = vec.begin();
$ for( ; itor != vec.end();itor ++)
$ {
$ 	cout << * itor << endl;
$ };

Similar to:

$ vector<T> vec;
$ for ( i = 0; i < vec.size(); i ++)
$ {
$ 	cout << vec[i] << endl;
$ };

2. list

list contains all functions vector. Traversal, however, can only be executed with iterator.

Define a list

$ list<int> l;
$ l.push_back(1);
$ l.push_back(3);
$ l.push_back(5);
$ l.push_back(1);
$ l.pop_back();

Traversal

$ list<int>::iterator itor = l.begin();
$ for ( ; itor != l.end(); itor++)
$ {
$	cout << *itor << endl;
$ };

compile error:

$ for( i = 0; i < l.size(); i++)
$ {
$	cout << list[i] <<endl; \encounter some error here
$ };

3. map