Sinh_Tap_Con_K_Cua

// Sinh_Tap_Con_K_Cua_N.cpp
#include <bits/stdc++.h>

using namespace std;

//Sinh cau hinh moi tu cau hinh dang co
void next_config(int x[], int k, int i) {
    x[i] += 1;
    i++;
    while (i <= k) { //x[i+1], ..., x[k] = can duoi
        x[i] = x[i - 1] + 1;
        i++;
    }
}

//Hien thi mot cau hinh
void view_config(int x[], int k) {
    for (int i = 1; i <= k; i++)
        cout << x[i];
    cout << endl;
}

//Liet ke cac cau hinh
void listing_configs(int k, int n) {
    int i;
    //x[k + 1] = { 0 };
    int x[k + 1];
    for (i = 0; i <= k; i++) x[i] = 0;
    //Cau hinh dau tien {1 2 ... k}
    for (i = 1; i <= k; i++) {
        x[i] = i;
    }
    do {
        view_config(x, k); //In mot cau hinh
        //Tim phan tu dau tien chua dat gh tren
        i = k;
        while (i > 0 && x[i] == n - k + i)
            i--;
        if (i > 0) { //Chua phai cau hinh cuoi
            next_config(x, k, i);
        }
    } while (i > 0);
}

int main() {
	int n, k;
	cout << "Nhap n: ";
	cin >> n;
	cout << "Nhap k: ";
	cin >> k;
	listing_configs(k, n);
	return 0;
}