ZBP1-3.cpp

#include <algorithm>
#include <iostream>
#include <string>
#include <vector>

using namespace std;

void ShowCollection(vector<char> &v);
void ShowCollection(int arr[], int size);
void testOnArrayOfInts();
void testOnVectorOfChars();
template<class BidirectionalIterator>
bool next_combination(BidirectionalIterator allRangeBegin,
		BidirectionalIterator allRangeEnd,
		BidirectionalIterator combinationRangeBegin,
		BidirectionalIterator combinationRangeEnd);

int main() {
	testOnArrayOfInts();
	testOnVectorOfChars();

	return 0;
}

void testOnVectorOfChars() {
	char tab[10] = { 'A', 'B', 'C', 'E', 'G', 'I', 'M', 'O', 'P', 'Y' };
	vector<char> vc(tab, tab + 3);
	vector<char> vi(tab, tab + 6);

	do {
		ShowCollection(vc);
	} while (next_combination(vi.begin(), vi.end(), vc.begin(), vc.end()));
}

void testOnArrayOfInts() {
	int tab[6] = { 1, 2, 3, 4, 5, 6 };
	int comb[3] = { 1, 2, 3 };

	do {
		ShowCollection(comb, 3);
	} while (next_combination(tab, tab + 6, comb, comb + 3));
}

template<class BidirectionalIterator>
bool next_combination(BidirectionalIterator allRangeBegin,
		BidirectionalIterator allRangeEnd,
		BidirectionalIterator combinationRangeBegin,
		BidirectionalIterator combinationRangeEnd) {

	for (BidirectionalIterator lastInCombination = combinationRangeEnd - 1,
			lastInRange = allRangeEnd - 1;
			lastInCombination >= combinationRangeBegin;
			--lastInCombination, --lastInRange) {
		if (*lastInCombination < *lastInRange) {
			BidirectionalIterator nextValue = find(allRangeBegin, allRangeEnd, *lastInCombination) + 1;

			while (lastInCombination != combinationRangeEnd) {
				*lastInCombination++ = *nextValue++;
			}

			return true;
		}
	}

	return false;
}

void ShowCollection(vector<char> &v) {
	for (vector<char>::iterator it = v.begin(); it != v.end(); it++) {
		cout << *it;
	}
	cout << " " << endl;
}

void ShowCollection(int arr[], int size) {
	for (int i = 0; i < size; i++) {
		cout << arr[i];
	}
	cout << " " << endl;
}