4977026daf 2012-01-14        kinaba: #include <iostream>
4977026daf 2012-01-14        kinaba: #include <sstream>
4977026daf 2012-01-14        kinaba: #include <iomanip>
4977026daf 2012-01-14        kinaba: #include <vector>
4977026daf 2012-01-14        kinaba: #include <string>
4977026daf 2012-01-14        kinaba: #include <map>
4977026daf 2012-01-14        kinaba: #include <set>
4977026daf 2012-01-14        kinaba: #include <algorithm>
4977026daf 2012-01-14        kinaba: #include <numeric>
4977026daf 2012-01-14        kinaba: #include <iterator>
4977026daf 2012-01-14        kinaba: #include <functional>
4977026daf 2012-01-14        kinaba: #include <complex>
4977026daf 2012-01-14        kinaba: #include <queue>
4977026daf 2012-01-14        kinaba: #include <stack>
4977026daf 2012-01-14        kinaba: #include <cmath>
4977026daf 2012-01-14        kinaba: #include <cassert>
4977026daf 2012-01-14        kinaba: #include <cstring>
4977026daf 2012-01-14        kinaba: #ifdef __GNUC__
4977026daf 2012-01-14        kinaba: #include <ext/hash_map>
4977026daf 2012-01-14        kinaba: #define unordered_map __gnu_cxx::hash_map
4977026daf 2012-01-14        kinaba: #else
4977026daf 2012-01-14        kinaba: #include <unordered_map>
4977026daf 2012-01-14        kinaba: #endif
4977026daf 2012-01-14        kinaba: using namespace std;
4977026daf 2012-01-14        kinaba: typedef long long LL;
4977026daf 2012-01-14        kinaba: typedef complex<double> CMP;
4977026daf 2012-01-14        kinaba: 
4977026daf 2012-01-14        kinaba: class TheDictionary { public:
4977026daf 2012-01-14        kinaba: 	string find(int n, int m, int k)
4977026daf 2012-01-14        kinaba: 	{
4977026daf 2012-01-14        kinaba: 		if( k <= C(n+m,n) )
4977026daf 2012-01-14        kinaba: 			return rec(n, m, k);
4977026daf 2012-01-14        kinaba: 		return "";
4977026daf 2012-01-14        kinaba: 	}
4977026daf 2012-01-14        kinaba: 
4977026daf 2012-01-14        kinaba: 	string rec(int n, int m, int k)
4977026daf 2012-01-14        kinaba: 	{
4977026daf 2012-01-14        kinaba: 		if( n+m == 0 )
4977026daf 2012-01-14        kinaba: 			return "";
4977026daf 2012-01-14        kinaba: 		if( n==0 )
4977026daf 2012-01-14        kinaba: 			return "z" + rec(n, m-1, k);
4977026daf 2012-01-14        kinaba: 		if( m==0 )
4977026daf 2012-01-14        kinaba: 			return "a" + rec(n-1, m, k);
4977026daf 2012-01-14        kinaba: 
4977026daf 2012-01-14        kinaba: 		LL c = C(n+m-1, m);
4977026daf 2012-01-14        kinaba: 		if( k <= c )
4977026daf 2012-01-14        kinaba: 			return "a" + rec(n-1, m, k);
4977026daf 2012-01-14        kinaba: 		return "z" + rec(n, m-1, k - c);
4977026daf 2012-01-14        kinaba: 	}
4977026daf 2012-01-14        kinaba: 
4977026daf 2012-01-14        kinaba: 	LL C(int n, int k)
4977026daf 2012-01-14        kinaba: 	{
4977026daf 2012-01-14        kinaba: 		k = min(k, n-k);
4977026daf 2012-01-14        kinaba: 		LL v = 1;
4977026daf 2012-01-14        kinaba: 		for(int i=1; i<=k; ++i) {
4977026daf 2012-01-14        kinaba: 			v = v * (n+1-i) / i;
4977026daf 2012-01-14        kinaba: 			if( v >= (1LL<<50) )
4977026daf 2012-01-14        kinaba: 				return v;
4977026daf 2012-01-14        kinaba: 		}
4977026daf 2012-01-14        kinaba: 		return v;
4977026daf 2012-01-14        kinaba: 	}
4977026daf 2012-01-14        kinaba: };
4977026daf 2012-01-14        kinaba: 
4977026daf 2012-01-14        kinaba: // BEGIN CUT HERE
4977026daf 2012-01-14        kinaba: #include <ctime>
4977026daf 2012-01-14        kinaba: double start_time; string timer()
4977026daf 2012-01-14        kinaba:  { ostringstream os; os << " (" << int((clock()-start_time)/CLOCKS_PER_SEC*1000) << " msec)"; return os.str(); }
4977026daf 2012-01-14        kinaba: template<typename T> ostream& operator<<(ostream& os, const vector<T>& v)
4977026daf 2012-01-14        kinaba:  { os << "{ ";
4977026daf 2012-01-14        kinaba:    for(typename vector<T>::const_iterator it=v.begin(); it!=v.end(); ++it)
4977026daf 2012-01-14        kinaba:    os << '\"' << *it << '\"' << (it+1==v.end() ? "" : ", "); os << " }"; return os; }
4977026daf 2012-01-14        kinaba: void verify_case(const string& Expected, const string& Received) {
4977026daf 2012-01-14        kinaba:  bool ok = (Expected == Received);
4977026daf 2012-01-14        kinaba:  if(ok) cerr << "PASSED" << timer() << endl;  else { cerr << "FAILED" << timer() << endl;
4977026daf 2012-01-14        kinaba:  cerr << "\to: \"" << Expected << '\"' << endl << "\tx: \"" << Received << '\"' << endl; } }
4977026daf 2012-01-14        kinaba: #define CASE(N) {cerr << "Test Case #" << N << "..." << flush; start_time=clock();
4977026daf 2012-01-14        kinaba: #define END	 verify_case(_, TheDictionary().find(n, m, k));}
4977026daf 2012-01-14        kinaba: int main(){
4977026daf 2012-01-14        kinaba: 
4977026daf 2012-01-14        kinaba: CASE(0)
4977026daf 2012-01-14        kinaba: 	int n = 2;
4977026daf 2012-01-14        kinaba: 	int m = 2;
4977026daf 2012-01-14        kinaba: 	int k = 2;
4977026daf 2012-01-14        kinaba: 	string _ = "azaz";
4977026daf 2012-01-14        kinaba: END
4977026daf 2012-01-14        kinaba: CASE(1)
4977026daf 2012-01-14        kinaba: 	int n = 2;
4977026daf 2012-01-14        kinaba: 	int m = 2;
4977026daf 2012-01-14        kinaba: 	int k = 6;
4977026daf 2012-01-14        kinaba: 	string _ = "zzaa";
4977026daf 2012-01-14        kinaba: END
4977026daf 2012-01-14        kinaba: CASE(2)
4977026daf 2012-01-14        kinaba: 	int n = 10;
4977026daf 2012-01-14        kinaba: 	int m = 10;
4977026daf 2012-01-14        kinaba: 	int k = 1000000000;
4977026daf 2012-01-14        kinaba: 	string _ = "";
4977026daf 2012-01-14        kinaba: END
4977026daf 2012-01-14        kinaba: CASE(3)
4977026daf 2012-01-14        kinaba: 	int n = 7;
4977026daf 2012-01-14        kinaba: 	int m = 4;
4977026daf 2012-01-14        kinaba: 	int k = 47;
4977026daf 2012-01-14        kinaba: 	string _ = "aaazazaazaz";
4977026daf 2012-01-14        kinaba: END
4977026daf 2012-01-14        kinaba: /*
4977026daf 2012-01-14        kinaba: CASE(4)
4977026daf 2012-01-14        kinaba: 	int n = ;
4977026daf 2012-01-14        kinaba: 	int m = ;
4977026daf 2012-01-14        kinaba: 	int k = ;
4977026daf 2012-01-14        kinaba: 	string _ = ;
4977026daf 2012-01-14        kinaba: END
4977026daf 2012-01-14        kinaba: CASE(5)
4977026daf 2012-01-14        kinaba: 	int n = ;
4977026daf 2012-01-14        kinaba: 	int m = ;
4977026daf 2012-01-14        kinaba: 	int k = ;
4977026daf 2012-01-14        kinaba: 	string _ = ;
4977026daf 2012-01-14        kinaba: END
4977026daf 2012-01-14        kinaba: */
4977026daf 2012-01-14        kinaba: }
4977026daf 2012-01-14        kinaba: // END CUT HERE