kimbits half

gistfile1.txt

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<string>
#define MAXN 33
#define INF 0x3f3f3f3f
using namespace std;
int size[MAXN][MAXN];
string ans;
int n, l, nth;
void printbits(int n, int l, int nth);
int main()
{
    memset(size, 0, sizeof(size));
    size[1][1] = 1;
    scanf("%d %d %d", &n, &l, &nth);
    for(int i=1; i<=n; i++)
        size[i][0] = 1, size[i][i] = 1;
    for(int i=2; i<=n; i++)
        for(int j=1; j<i; j++)
            size[i][j] = size[i-1][j] + size[i-1][j-1];
    for(int i=1; i<=n; i++)
        for(int j=1; j<=i; j++)
            size[i][j] += size[i][j-1];
    
    printbits(n, l, nth);
    cout<<ans<<endl;

}
void printbits(int n, int l, int nth)
{
    if (nth == 1) { ans += '0'; return;}
    if (nth == 2) { ans += '1'; return;}


    if (size[n - 1][l] >= nth )
    {
        ans += '0';
        printbits(n-1, l, nth);
    }
    else
    {
        ans += '1';
        printbits(n-1, l-1, nth - size[n-1][l]);
    }
}