adjacent_find: search first two elements for which the second has double the value of the first
/* 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>
using namespace std;
/* 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);
}
}
// return whether the second object has double the value of the first
bool doubled (int elem1, int elem2)
{
return elem1 * 2 == elem2;
}
int main()
{
vector<int> coll;
coll.push_back(1);
coll.push_back(3);
coll.push_back(2);
coll.push_back(4);
coll.push_back(5);
coll.push_back(5);
coll.push_back(0);
PRINT_ELEMENTS(coll,"coll: ");
vector<int>::iterator pos;
// search first two elements for which the second has double the value of the first
pos = adjacent_find (coll.begin(), coll.end(), // range
doubled); // criterion
if (pos != coll.end()) {
cout << "first two elements with second value twice the "
<< "first have pos. "
<< distance(coll.begin(),pos) + 1
<< endl;
}
}coll: 1 3 2 4 5 5 0
first two elements with second value twice the first have pos. 3
adjacent_find: search first two elements with equal value
/* 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>
using namespace std;
/* 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);
}
}
// return whether the second object has double the value of the first
bool doubled (int elem1, int elem2)
{
return elem1 * 2 == elem2;
}
int main()
{
vector<int> coll;
coll.push_back(1);
coll.push_back(3);
coll.push_back(2);
coll.push_back(4);
coll.push_back(5);
coll.push_back(5);
coll.push_back(0);
PRINT_ELEMENTS(coll,"coll: ");
// search first two elements with equal value
vector<int>::iterator pos;
pos = adjacent_find (coll.begin(), coll.end());
if (pos != coll.end()) {
cout << "first two elements with equal value have position "
<< distance(coll.begin(),pos) + 1
<< endl;
}
}coll: 1 3 2 4 5 5 0
first two elements with equal value have position 5
Illustrating the generic adjacent_find algorithm
#include <iostream>
#include <string>
#include <algorithm>
#include <cassert>
#include <functional>
#include <deque>
using namespace std;
int main()
{
deque<string> player(5);
deque<string>::iterator i;
player[0] = "PPPP";
player[1] = "AAAAAA";
player[2] = "AAAAAA";
player[3] = "NNNNNNNN";
player[4] = "RRRRRRRRR";
// Find the first pair of equal consecutive names:
i = adjacent_find(player.begin(), player.end());
cout << *i;
return 0;
}AAAAAA"
Use generic adjacent_find algorithm with a predicate to find the first name that is lexicographically greater than the next one
#include <iostream>
#include <string>
#include <algorithm>
#include <cassert>
#include <functional>
#include <deque>
using namespace std;
int main()
{
deque<string> player(5);
deque<string>::iterator i;
player[0] = "PPPP";
player[1] = "AAAAAA";
player[2] = "AAAAAA";
player[3] = "NNNNNNNN";
player[4] = "RRRRRRRRR";
i = adjacent_find(player.begin(), player.end(), greater<string>());
cout << *i << endl;
return 0;
}PPPP
