C++/STL Algorithms Non modifying sequence operations/find end
Версия от 14:21, 25 мая 2010; (обсуждение)
Use find_end to search last occurrence of subcoll in coll
/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/
#include <iostream>
#include <vector>
#include <deque>
#include <list>
#include <set>
#include <map>
#include <string>
#include <algorithm>
#include <iterator>
#include <functional>
#include <numeric>
/* PRINT_ELEMENTS()
* - prints optional C-string optcstr followed by
* - all elements of the collection coll
* - separated by spaces
*/
template <class T>
inline void PRINT_ELEMENTS (const T& coll, const char* optcstr="")
{
typename T::const_iterator pos;
std::cout << optcstr;
for (pos=coll.begin(); pos!=coll.end(); ++pos) {
std::cout << *pos << " ";
}
std::cout << std::endl;
}
/* INSERT_ELEMENTS (collection, first, last)
* - fill values from first to last into the collection
* - NOTE: NO half-open range
*/
template <class T>
inline void INSERT_ELEMENTS (T& coll, int first, int last)
{
for (int i=first; i<=last; ++i) {
coll.insert(coll.end(),i);
}
}
using namespace std;
int main()
{
deque<int> coll;
list<int> subcoll;
INSERT_ELEMENTS(coll,1,7);
INSERT_ELEMENTS(coll,1,7);
INSERT_ELEMENTS(subcoll,3,6);
PRINT_ELEMENTS(coll, "coll: ");
PRINT_ELEMENTS(subcoll,"subcoll: ");
// search last occurrence of subcoll in coll
deque<int>::iterator pos;
pos = find_end (coll.begin(), coll.end(), // range
subcoll.begin(), subcoll.end()); // subrange
// print its position
cout << distance(coll.begin(),pos) + 1 << endl;
}
/*
coll: 1 2 3 4 5 6 7 1 2 3 4 5 6 7
subcoll: 3 4 5 6
10
*/
Use find_end with while loop to find the element
/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/
#include <iostream>
#include <vector>
#include <deque>
#include <list>
#include <set>
#include <map>
#include <string>
#include <algorithm>
#include <iterator>
#include <functional>
#include <numeric>
/* PRINT_ELEMENTS()
* - prints optional C-string optcstr followed by
* - all elements of the collection coll
* - separated by spaces
*/
template <class T>
inline void PRINT_ELEMENTS (const T& coll, const char* optcstr="")
{
typename T::const_iterator pos;
std::cout << optcstr;
for (pos=coll.begin(); pos!=coll.end(); ++pos) {
std::cout << *pos << " ";
}
std::cout << std::endl;
}
/* INSERT_ELEMENTS (collection, first, last)
* - fill values from first to last into the collection
* - NOTE: NO half-open range
*/
template <class T>
inline void INSERT_ELEMENTS (T& coll, int first, int last)
{
for (int i=first; i<=last; ++i) {
coll.insert(coll.end(),i);
}
}
using namespace std;
int main()
{
deque<int> coll;
list<int> subcoll;
INSERT_ELEMENTS(coll,1,7);
INSERT_ELEMENTS(coll,1,7);
INSERT_ELEMENTS(subcoll,3,6);
PRINT_ELEMENTS(coll, "coll: ");
PRINT_ELEMENTS(subcoll,"subcoll: ");
// search last occurrence of subcoll in coll
deque<int>::iterator pos;
pos = find_end (coll.begin(), coll.end(), // range
subcoll.begin(), subcoll.end()); // subrange
// loop while subcoll found as subrange of coll
deque<int>::iterator end(coll.end());
while (pos != end) {
// print position of first element
cout << "subcoll found starting with element "
<< distance(coll.begin(),pos) + 1
<< endl;
// search next occurrence of subcoll
end = pos;
pos = find_end (coll.begin(), end, // range
subcoll.begin(), subcoll.end()); // subrange
// print its position
cout << distance(coll.begin(),pos) + 1 << endl;
}
}
/*
coll: 1 2 3 4 5 6 7 1 2 3 4 5 6 7
subcoll: 3 4 5 6
subcoll found starting with element 10
3
subcoll found starting with element 3
3
*/