C++/Vector/vector push pop heap
Содержание
Demonstrating the STL vector push_back functions
#include <iostream>
#include <cassert>
#include <vector>
#include <string>
#include <algorithm> // for reverse
using namespace std;
int main()
{
string s("qwer");
vector<char> vector1(s.begin(), s.end());
vector<char> vector2;
vector<char>::iterator i;
for (i = vector1.begin(); i != vector1.end(); ++i)
vector2.push_back(*i);
for (i = vector2.begin(); i != vector2.end(); ++i)
cout << *i;
return 0;
}
/*
qwer
*/
Inserting Elements in a vector Using the push_back Method
#include <iostream>
#include <vector>
int main ()
{
std::vector <int> v;
// Insert sample integers into the vector
v.push_back (50);
v.push_back (1);
v.push_back (987);
v.push_back (1001);
std::cout << v.size () << " Elements";
return 0;
}
Perform the heapsort with push_heap and pop_heap
#include <iostream>
using std::cout;
using std::endl;
#include <algorithm>
#include <vector>
#include <iterator>
int main()
{
int a[ 10 ] = { 3, 10, 2, 7, 4, 8, 1, 9, 5, 6 };
std::vector< int > v( a, a + 10 ); // copy of a
std::vector< int > v2;
std::ostream_iterator< int > output( cout, " " );
for ( int i = 0; i < 10; i++ )
{
v2.push_back( a[ i ] );
std::push_heap( v2.begin(), v2.end() );
cout << "\nv2 after push_heap(a[" << i << "]): ";
std::copy( v2.begin(), v2.end(), output );
}
for ( int j = 0; j < v2.size(); j++ )
{
cout << "\nv2 after " << v2[ 0 ] << " popped from heap\n";
std::pop_heap( v2.begin(), v2.end() - j );
std::copy( v2.begin(), v2.end(), output );
}
cout << endl;
return 0;
}
/*
v2 after push_heap(a[0]): 3
v2 after push_heap(a[1]): 10 3
v2 after push_heap(a[2]): 10 3 2
v2 after push_heap(a[3]): 10 7 2 3
v2 after push_heap(a[4]): 10 7 2 3 4
v2 after push_heap(a[5]): 10 7 8 3 4 2
v2 after push_heap(a[6]): 10 7 8 3 4 2 1
v2 after push_heap(a[7]): 10 9 8 7 4 2 1 3
v2 after push_heap(a[8]): 10 9 8 7 4 2 1 3 5
v2 after push_heap(a[9]): 10 9 8 7 6 2 1 3 5 4
v2 after 10 popped from heap
9 7 8 5 6 2 1 3 4 10
v2 after 9 popped from heap
8 7 4 5 6 2 1 3 9 10
v2 after 8 popped from heap
7 6 4 5 3 2 1 8 9 10
v2 after 7 popped from heap
6 5 4 1 3 2 7 8 9 10
v2 after 6 popped from heap
5 3 4 1 2 6 7 8 9 10
v2 after 5 popped from heap
4 3 2 1 5 6 7 8 9 10
v2 after 4 popped from heap
3 1 2 4 5 6 7 8 9 10
v2 after 3 popped from heap
2 1 3 4 5 6 7 8 9 10
v2 after 2 popped from heap
1 2 3 4 5 6 7 8 9 10
v2 after 1 popped from heap
1 2 3 4 5 6 7 8 9 10
*/
Read data from a file and save that to vector
#include <algorithm>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <numeric>
#include <vector>
using namespace std;
int main( )
{
ifstream stock_file( "data.txt" );
vector<float> price( (istream_iterator<float>( stock_file )),istream_iterator<float>() );
vector<float> percent_change( price.size() );
adjacent_difference( price.begin(), price.end(),percent_change.begin() );
copy( price.begin(), price.begin()+5,ostream_iterator<float>( cout, " " ) );
}