4fd800b3a8 2011-02-23        kinaba: #include <iostream>
4fd800b3a8 2011-02-23        kinaba: #include <sstream>
4fd800b3a8 2011-02-23        kinaba: #include <iomanip>
4fd800b3a8 2011-02-23        kinaba: #include <vector>
4fd800b3a8 2011-02-23        kinaba: #include <string>
4fd800b3a8 2011-02-23        kinaba: #include <map>
4fd800b3a8 2011-02-23        kinaba: #include <set>
4fd800b3a8 2011-02-23        kinaba: #include <algorithm>
4fd800b3a8 2011-02-23        kinaba: #include <numeric>
4fd800b3a8 2011-02-23        kinaba: #include <iterator>
4fd800b3a8 2011-02-23        kinaba: #include <complex>
4fd800b3a8 2011-02-23        kinaba: #include <queue>
4fd800b3a8 2011-02-23        kinaba: #include <stack>
4fd800b3a8 2011-02-23        kinaba: #include <cmath>
4fd800b3a8 2011-02-23        kinaba: using namespace std;
4fd800b3a8 2011-02-23        kinaba: typedef long long LL;
4fd800b3a8 2011-02-23        kinaba: 
4fd800b3a8 2011-02-23        kinaba: class KLastNonZeroDigits
4fd800b3a8 2011-02-23        kinaba: {
4fd800b3a8 2011-02-23        kinaba: public:
4fd800b3a8 2011-02-23        kinaba: 	string getKDigits(int N, int K)
4fd800b3a8 2011-02-23        kinaba: 	{
4fd800b3a8 2011-02-23        kinaba: 		// 20! = 20*..*11*10! < 20*..*11*2^22
4fd800b3a8 2011-02-23        kinaba: 		//                    < 16^10 * 2^22
4fd800b3a8 2011-02-23        kinaba: 		//                    = 2^62
4fd800b3a8 2011-02-23        kinaba: 
4fd800b3a8 2011-02-23        kinaba: 		// 10^K
4fd800b3a8 2011-02-23        kinaba: 		LL Z = 1;
4fd800b3a8 2011-02-23        kinaba: 		for(int i=0; i<K; ++i)
4fd800b3a8 2011-02-23        kinaba: 			Z *= 10;
4fd800b3a8 2011-02-23        kinaba: 
4fd800b3a8 2011-02-23        kinaba: 		// N!
4fd800b3a8 2011-02-23        kinaba: 		LL x = 1;
4fd800b3a8 2011-02-23        kinaba: 		for(LL n=2; n<=N; ++n)
4fd800b3a8 2011-02-23        kinaba: 			x *= n;
4fd800b3a8 2011-02-23        kinaba: 		while(x%10==0)
4fd800b3a8 2011-02-23        kinaba: 			x /= 10;
4fd800b3a8 2011-02-23        kinaba: 
4fd800b3a8 2011-02-23        kinaba: 		// Output
4fd800b3a8 2011-02-23        kinaba: 		stringstream sout;
4fd800b3a8 2011-02-23        kinaba: 		if( x < Z )
4fd800b3a8 2011-02-23        kinaba: 			sout << x;
4fd800b3a8 2011-02-23        kinaba: 		else
4fd800b3a8 2011-02-23        kinaba: 			sout << setw(K) << setfill('0') << x%Z;
4fd800b3a8 2011-02-23        kinaba: 		return sout.str();
4fd800b3a8 2011-02-23        kinaba: 	}
4fd800b3a8 2011-02-23        kinaba: 
4fd800b3a8 2011-02-23        kinaba: // BEGIN CUT HERE
4fd800b3a8 2011-02-23        kinaba: 	public:
4fd800b3a8 2011-02-23        kinaba: 	void run_test(int Case) { if ((Case == -1) || (Case == 0)) test_case_0(); if ((Case == -1) || (Case == 1)) test_case_1(); if ((Case == -1) || (Case == 2)) test_case_2(); if ((Case == -1) || (Case == 3)) test_case_3(); if ((Case == -1) || (Case == 4)) test_case_4(); if ((Case == -1) || (Case == 5)) test_case_5(); }
4fd800b3a8 2011-02-23        kinaba: 	private:
4fd800b3a8 2011-02-23        kinaba: 	template <typename T> string print_array(const vector<T> &V) { ostringstream os; os << "{ "; for (typename vector<T>::const_iterator iter = V.begin(); iter != V.end(); ++iter) os << '\"' << *iter << "\","; os << " }"; return os.str(); }
4fd800b3a8 2011-02-23        kinaba: 	void verify_case(int Case, const string &Expected, const string &Received) { cerr << "Test Case #" << Case << "..."; if (Expected == Received) cerr << "PASSED" << endl; else { cerr << "FAILED" << endl; cerr << "\tExpected: \"" << Expected << '\"' << endl; cerr << "\tReceived: \"" << Received << '\"' << endl; } }
4fd800b3a8 2011-02-23        kinaba: 	void test_case_0() { int Arg0 = 10; int Arg1 = 3; string Arg2 = "288"; verify_case(0, Arg2, getKDigits(Arg0, Arg1)); }
4fd800b3a8 2011-02-23        kinaba: 	void test_case_1() { int Arg0 = 6; int Arg1 = 1; string Arg2 = "2"; verify_case(1, Arg2, getKDigits(Arg0, Arg1)); }
4fd800b3a8 2011-02-23        kinaba: 	void test_case_2() { int Arg0 = 6; int Arg1 = 3; string Arg2 = "72"; verify_case(2, Arg2, getKDigits(Arg0, Arg1)); }
4fd800b3a8 2011-02-23        kinaba: 	void test_case_3() { int Arg0 = 7; int Arg1 = 2; string Arg2 = "04"; verify_case(3, Arg2, getKDigits(Arg0, Arg1)); }
4fd800b3a8 2011-02-23        kinaba: 	void test_case_4() { int Arg0 = 20; int Arg1 = 9; string Arg2 = "200817664"; verify_case(4, Arg2, getKDigits(Arg0, Arg1)); }
4fd800b3a8 2011-02-23        kinaba: 	void test_case_5() { int Arg0 = 1; int Arg1 = 1; string Arg2 = "1"; verify_case(5, Arg2, getKDigits(Arg0, Arg1)); }
4fd800b3a8 2011-02-23        kinaba: 
4fd800b3a8 2011-02-23        kinaba: // END CUT HERE
4fd800b3a8 2011-02-23        kinaba: };
4fd800b3a8 2011-02-23        kinaba: // BEGIN CUT HERE
4fd800b3a8 2011-02-23        kinaba: int main() { KLastNonZeroDigits().run_test(-1); }
4fd800b3a8 2011-02-23        kinaba: // END CUT HERE