All possible permutation

#include <iostream> #include <vector> using namespace std; int factorial(int n) { if (n<2) { return 1; } else { return n*factorial(n - 1); } } vector<int> insert(vector<int> arr, int pos, int val) { vector <int> temp(arr.size()+1); for (int i = 0; i < pos; i++) { temp[i] = arr[i]; } for (int i = arr.size(); i > pos; i--) { temp[i] = arr[i - 1]; } temp[pos] = val; return temp; } void disparr(int *arr, int sz) { for (int i = 0; i < sz; i++) { cout << arr[i] << ' '; } cout << endl; } void disparr(vector<int> a) { for (int i = 0; i < a.size(); i++) { cout << a[i] << ' '; } cout << endl; } vector<vector<int>> combmaker(vector<vector<int>> a, int elem) { vector<vector<int>> retval(factorial(a[0].size() + 1)); vector<int> b(a[0].size()+1,0); for (int i = 0; i < retval.size(); i++) { retval[i] = b; } for (int i = 0; i < a[0].size() + 1; i++) { for (int j = 0; j < factorial(a[0].size()); j++) { retval[i * factorial(a[0].size()) + j] = insert(a[j], i, elem); //disparr(temp4[i * factorial(4) + j], 5); } } return retval; } void disparr2d(vector<vector<int>> a) { for (int i = 0; i < a.size(); i++) { for (int j = 0; j < a[i].size(); j++) { cout << a[i][j] << ' '; } cout << endl; } } int main() { vector <int> a = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 }; // set of numbers to make permutation vector<vector <int>> b; vector<vector<int>> init; vector<int> inite = {a[0]}; init.push_back(inite); b = combmaker(init, a[1]); for (int i = 2; i < a.size(); i++) { b = combmaker(b, a[i]); disparr2d(b); cout << "finised " << i << " th iteration" << endl; } disparr2d(b); return 0; }