C++ Tutorial/list/list assign
Содержание
make a list from a list with list_copy()
<source lang="cpp">#include <iomanip>
- include <iostream>
- include <list>
- include <vector>
using namespace std; template <class T> void print(T& c){
for( typename T::iterator i = c.begin(); i != c.end(); i++ ){ std::cout << *i << endl; }
} int main( ) {
const int data[] = { 1, 1, 2, 3, 5 }; list<int> original( data,data + sizeof( data ) / sizeof( data[0] ) ); // make a list from a list list<int> list_copy( original ); // show results print( original); print( list_copy);
}</source>
make a list of floats from a list of ints
<source lang="cpp">#include <iomanip>
- include <iostream>
- include <list>
- include <vector>
using namespace std; template <class T> void print(T& c){
for( typename T::iterator i = c.begin(); i != c.end(); i++ ){ std::cout << *i << endl; }
} int main( ) {
const int data[] = { 1, 1, 2, 3, 5 }; list<int> original( data,data + sizeof( data ) / sizeof( data[0] ) ); // make a list of floats from a list of ints list<float> list_float( original.begin(), original.end() ); // show results print( original); print( list_float );
}</source>
populate a new list with the elements of list2
<source lang="cpp">#include <list>
- include <string>
- include <iostream>
using namespace std; int main() {
list<int> list1; size_t n = 10; double val = 3.14; list<double> list2(n, val); list<double> list3(list2); cout << "Size of list1 " << list1.size() << endl; cout << "Size of list2 " << list2.size() << endl; cout << "Size of list3 " << list3.size() << endl; // populate a new list with the elements of list2 list<double> list4; list<double>::const_iterator i; for (i = list2.begin(); i != list2.end(); ++i) { list4.push_back(*i); } // Print every character in the list for (i = list4.begin(); i != list4.end(); ++i) { cout << *i << ","; } cout << endl; return 0;
}</source>
Use list.assign to replace contents of a list with elements of another list
<source lang="cpp">#include <iostream> using std::cout; using std::endl;
- include <list> // list class-template definition
- include <algorithm> // copy algorithm
- include <iterator> // ostream_iterator
int main() {
int array[ 4 ] = { 2, 6, 4, 8 }; std::list< int > values; // create list of ints std::list< int > otherValues; // create list of ints std::ostream_iterator< int > output( cout, " " ); // insert items in values values.push_front( 1 ); values.push_front( 3 ); values.push_back( 4 ); values.push_back( 2 ); cout << "values contains: "; std::copy( values.begin(), values.end(), output ); otherValues.insert( otherValues.begin(), array, array + 4 ); cout << "\n\notherValues contains: "; std::copy( otherValues.begin(), otherValues.end(), output );
values.assign( otherValues.begin(), otherValues.end() ); cout << "\n\nvalues contains: "; std::copy( values.begin(), values.end(), output ); cout << endl; return 0;
}</source>
values contains: 3 1 4 2 otherValues contains: 2 6 4 8 values contains: 2 6 4 8