Trick: Finding all the results is pretty easy using any Basic Backtracking code but you have to sort them. So? Don't work with 1s work with 0s. Or just use next_permutation( ) from STL, your choice. Optimizations: Pregenerating all combinations might give you a better runtime, didn't try it.
Sample Input:
1 16 7
Sample Output:
Please find it using UVA Toolkit (www.uvatoolkit.com)
/* Faith-M */
//Headers
#include <set>
#include <map>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <cctype>
#include <cstdio>
#include <string>
#include <vector>
#include <cassert>
#include <cstdlib>
#include <cstring>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <climits>
#include <clocale>
//Defines
#define pow2(i) (1<<i)
#define bit(i) (1<<i)
#define isOdd(i) (i&1)
#define isEven(i) (!(i&1))
#define isPrime(i) ((i==2) || ((i&1) && !pTest[i])) //pTest has to be the bool array's name
#define sz(i) i.size()
#define vec(type,name) vector< type > name
#define rep(i,a,b) for(int i=a ; i<=b ; i++)
#define swap(type,a,b) {type t=a; a=b; b=t;}
#define sum(a,n) ( (n*(n+1)/2) - (a-1)*a/2 )
#define iscap(i) (i>='A'&&i<='Z')
#define issmall(i) (i>='a'&&i<='z')
#define isnum(i) (i>='0'&&i<='9')
#define issymbol(i) (!(i>='a'&&i<='z') && !(i>='A'&&i<='Z') && !(i>='0'&&i<='9'))
#define mk(i,j) make_pair(i,j)
#define ERROR 1e-11
//Type Defs
typedef long long lint;
typedef unsigned long long ulint;
typedef long double ldouble;
using namespace std;
int st[20];
void func(int n, int h, int cnt, int x)
{
if (cnt >= h)
{
for (int j=1 ; j<=n ; j++)
{
printf("%d",st[j]);
}
printf("\n");
return;
}
for (int i=x ; i<=n ; i++)
{
if (st[i] == 1)
{
st[i] = 0;
func(n,h,cnt+1,i+1);
st[i] = 1;
}
}
return;
}
int main()
{
//freopen("input.txt","r+",stdin);
//freopen("output.txt","w+",stdout);/**/
// TEST CASE //
int kase=1, kounter=1;/**/
int n, h;
bool blnk = false;
scanf("%d",&kase);
while ( kase-- )
{
if (blnk) printf("\n");
else blnk = true;
for (int i=1 ; i<=20 ; i++)
{
st[i] = 1;
}
scanf("%d %d",&n,&h);
func(n,n-h,0,1);
}
return 0;
}
