[LeetCode]PermutationSequence

#include 
#include <string>
using namespace std;

class Solution {
public:
    string getPermutation(int n, int k) {
        if(n <2)    return "1";
        int tab[10]={1};
        for(int i =1;i<=9;i++)
            tab[i] = tab[i-1]*i;
        int remain[9]={0};
        for(int i=0;i<9;i++)
            remain[i]=i+1;
        int cnt = n;
        string ret = "";
        while(cnt>0){
            cnt--;
            int num = (k-1)/tab[cnt];
//            cout<<"num="<
            int idx = 0;
            while(remain[idx]==0)   idx++;
            for(int i=0;i)
                if(remain[++idx]==0)  i--;
//            cout<<"idx="<
            ret += '0'+remain[idx];
            remain[idx]=0;
            k = k - num*tab[cnt];
//            cout<
        }
        return ret;
    }
};

int main()
{
    Solution sol;
    cout<9,213)<<endl;
    return 0;
}