#include <iostream>
#include <vector>
std::vector<char> combination;
void print(const std::vector<char>& v) {
static int count = 0;
for (int i = 0; i < v.size(); ++i) {
std::cout << v[i] << " ";
}
std::cout << "\n";
}
void generate(const std::vector<char>& characters, int start, int Ncombinations) {
if (Ncombinations == 0) {
print(combination);
return;
}
for (int i = start; i <= characters.size() - Ncombinations; i++) {
combination.push_back(characters[i]);
generate(characters, i + 1, Ncombinations - 1);
combination.pop_back();
}
}
int main() {
int X_1_to_6 = 6, Ncombinations = 3;
std::vector<char> characters = {'a', 'b', 'c', 'd', 'e', 'f', 'g'};
generate(characters, 0, Ncombinations);
return 0;
}
/*
run:
a b c
a b d
a b e
a b f
a b g
a c d
a c e
a c f
a c g
a d e
a d f
a d g
a e f
a e g
a f g
b c d
b c e
b c f
b c g
b d e
b d f
b d g
b e f
b e g
b f g
c d e
c d f
c d g
c e f
c e g
c f g
d e f
d e g
d f g
e f g
*/
