Combination Idea

#include<iostream>
#include <vector>

using namespace std;

vector<int> people;

vector<int> combination;

void pretty_print(const vector<int>& v) {

static int count = 0;

cout << "combination no " << (++count) << ": [ ";

for (int i = 0; i < v.size(); ++i) { cout << v[i] << " "; }

cout << "] " << endl;

}

void go(int offset, int k) {

if (k == 0) {

pretty_print(combination);

return;

}

for (int i = offset; i <= people.size() - k; ++i) {

combination.push_back(people[i]);

go(i+1, k-1);

combination.pop_back();

}

}

int main() {

int n = 5, k = 3;

for (int i = 0; i < n; ++i) { people.push_back(i+1); }

go(0, k);

return 0;

}


/*

And here's output for N = 5, K = 3:

combination no 1: [ 1 2 3 ]

combination no 2: [ 1 2 4 ]

combination no 3: [ 1 2 5 ]

combination no 4: [ 1 3 4 ]

combination no 5: [ 1 3 5 ]

combination no 6: [ 1 4 5 ]

combination no 7: [ 2 3 4 ]

combination no 8: [ 2 3 5 ]

combination no 9: [ 2 4 5 ]

combination no 10: [ 3 4 5 ]

*/