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 <functional>
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: #include <cassert>
4fd800b3a8 2011-02-23        kinaba: #include <cstring>
4fd800b3a8 2011-02-23        kinaba: using namespace std;
4fd800b3a8 2011-02-23        kinaba: typedef long long LL;
4fd800b3a8 2011-02-23        kinaba: typedef complex<double> CMP;
4fd800b3a8 2011-02-23        kinaba: 
4fd800b3a8 2011-02-23        kinaba: class BinaryFlips { public:
4fd800b3a8 2011-02-23        kinaba: 	int minimalMoves(int A, int B, int K)
4fd800b3a8 2011-02-23        kinaba: 	{
4fd800b3a8 2011-02-23        kinaba: 		vector<int> visitedUpto(A+B+1, -1);
4fd800b3a8 2011-02-23        kinaba: 		visitedUpto[B] = B;
4fd800b3a8 2011-02-23        kinaba: 
4fd800b3a8 2011-02-23        kinaba: 		// Breadth-first search from the initial state (A,B)
4fd800b3a8 2011-02-23        kinaba: 		queue< pair<int,int> > q;
4fd800b3a8 2011-02-23        kinaba: 		q.push( make_pair(B, 0) );
4fd800b3a8 2011-02-23        kinaba: 		while( !q.empty() )
4fd800b3a8 2011-02-23        kinaba: 		{
4fd800b3a8 2011-02-23        kinaba: 			// pop state (a,b)
4fd800b3a8 2011-02-23        kinaba: 			int b=q.front().first, a=A+B-b, step=q.front().second; q.pop();
4fd800b3a8 2011-02-23        kinaba: 
4fd800b3a8 2011-02-23        kinaba: 			// if (a,b) == (0,A+B), done
4fd800b3a8 2011-02-23        kinaba: 			if( b == A+B )
4fd800b3a8 2011-02-23        kinaba: 				return step;
4fd800b3a8 2011-02-23        kinaba: 
4fd800b3a8 2011-02-23        kinaba: 			// for all possible next values (nb) of b...
4fd800b3a8 2011-02-23        kinaba: 			int nb_min = abs(b-K), nb_max = A+B-abs(a-K);
4fd800b3a8 2011-02-23        kinaba: 			for(int nb=nb_min; nb<=nb_max; nb+=2)
4fd800b3a8 2011-02-23        kinaba: 				if( visitedUpto[nb] == -1 )
4fd800b3a8 2011-02-23        kinaba: 				{
4fd800b3a8 2011-02-23        kinaba: 					// if not visited, push the new state to the queue
4fd800b3a8 2011-02-23        kinaba: 					q.push( make_pair(nb, step+1) );
4fd800b3a8 2011-02-23        kinaba: 					visitedUpto[nb] = nb_max;
4fd800b3a8 2011-02-23        kinaba: 				}
4fd800b3a8 2011-02-23        kinaba: 				else
4fd800b3a8 2011-02-23        kinaba: 				{
4fd800b3a8 2011-02-23        kinaba: 					// if visited, skip it
4fd800b3a8 2011-02-23        kinaba: 					int nb2 = visitedUpto[nb];
4fd800b3a8 2011-02-23        kinaba: 					visitedUpto[nb] = max(visitedUpto[nb], nb_max);
4fd800b3a8 2011-02-23        kinaba: 					nb = nb2;
4fd800b3a8 2011-02-23        kinaba: 				}
4fd800b3a8 2011-02-23        kinaba: 		}
4fd800b3a8 2011-02-23        kinaba: 		return -1;
4fd800b3a8 2011-02-23        kinaba: 	}
4fd800b3a8 2011-02-23        kinaba: };
4fd800b3a8 2011-02-23        kinaba: 
4fd800b3a8 2011-02-23        kinaba: // BEGIN CUT HERE
4fd800b3a8 2011-02-23        kinaba: #include <ctime>
4fd800b3a8 2011-02-23        kinaba: double start_time; string timer()
4fd800b3a8 2011-02-23        kinaba:  { ostringstream os; os << " (" << int((clock()-start_time)/CLOCKS_PER_SEC*1000) << " msec)"; return os.str(); }
4fd800b3a8 2011-02-23        kinaba: template<typename T> ostream& operator<<(ostream& os, const vector<T>& v)
4fd800b3a8 2011-02-23        kinaba:  { os << "{ ";
4fd800b3a8 2011-02-23        kinaba:    for(typename vector<T>::const_iterator it=v.begin(); it!=v.end(); ++it)
4fd800b3a8 2011-02-23        kinaba:    os << '\"' << *it << '\"' << (it+1==v.end() ? "" : ", "); os << " }"; return os; }
4fd800b3a8 2011-02-23        kinaba: void verify_case(const int& Expected, const int& Received) {
4fd800b3a8 2011-02-23        kinaba:  bool ok = (Expected == Received);
4fd800b3a8 2011-02-23        kinaba:  if(ok) cerr << "PASSED" << timer() << endl;  else { cerr << "FAILED" << timer() << endl;
4fd800b3a8 2011-02-23        kinaba:  cerr << "\to: \"" << Expected << '\"' << endl << "\tx: \"" << Received << '\"' << endl; } }
4fd800b3a8 2011-02-23        kinaba: #define CASE(N) {cerr << "Test Case #" << N << "..." << flush; start_time=clock();
4fd800b3a8 2011-02-23        kinaba: #define END	 verify_case(_, BinaryFlips().minimalMoves(A, B, K));}
4fd800b3a8 2011-02-23        kinaba: int main(){
4fd800b3a8 2011-02-23        kinaba: 
4fd800b3a8 2011-02-23        kinaba: CASE(0)
4fd800b3a8 2011-02-23        kinaba: 	int A = 3;
4fd800b3a8 2011-02-23        kinaba: 	int B = 0;
4fd800b3a8 2011-02-23        kinaba: 	int K = 3;
4fd800b3a8 2011-02-23        kinaba: 	int _ = 1;
4fd800b3a8 2011-02-23        kinaba: END
4fd800b3a8 2011-02-23        kinaba: CASE(1)
4fd800b3a8 2011-02-23        kinaba: 	int A = 4;
4fd800b3a8 2011-02-23        kinaba: 	int B = 0;
4fd800b3a8 2011-02-23        kinaba: 	int K = 3;
4fd800b3a8 2011-02-23        kinaba: 	int _ = 4;
4fd800b3a8 2011-02-23        kinaba: END
4fd800b3a8 2011-02-23        kinaba: CASE(2)
4fd800b3a8 2011-02-23        kinaba: 	int A = 4;
4fd800b3a8 2011-02-23        kinaba: 	int B = 1;
4fd800b3a8 2011-02-23        kinaba: 	int K = 3;
4fd800b3a8 2011-02-23        kinaba: 	int _ = 2;
4fd800b3a8 2011-02-23        kinaba: END
4fd800b3a8 2011-02-23        kinaba: CASE(3)
4fd800b3a8 2011-02-23        kinaba: 	int A = 3;
4fd800b3a8 2011-02-23        kinaba: 	int B = 2;
4fd800b3a8 2011-02-23        kinaba: 	int K = 5;
4fd800b3a8 2011-02-23        kinaba: 	int _ = -1;
4fd800b3a8 2011-02-23        kinaba: END
4fd800b3a8 2011-02-23        kinaba: CASE(4)
4fd800b3a8 2011-02-23        kinaba: 	int A = 100000;
4fd800b3a8 2011-02-23        kinaba: 	int B = 100000;
4fd800b3a8 2011-02-23        kinaba: 	int K = 578;
4fd800b3a8 2011-02-23        kinaba: 	int _ = 174;
4fd800b3a8 2011-02-23        kinaba: END
4fd800b3a8 2011-02-23        kinaba: CASE(5)
4fd800b3a8 2011-02-23        kinaba: 	int A = 0;
4fd800b3a8 2011-02-23        kinaba: 	int B = 0;
4fd800b3a8 2011-02-23        kinaba: 	int K = 1;
4fd800b3a8 2011-02-23        kinaba: 	int _ = 0;
4fd800b3a8 2011-02-23        kinaba: END
4fd800b3a8 2011-02-23        kinaba: CASE(6)
4fd800b3a8 2011-02-23        kinaba: 	int A = 4;
4fd800b3a8 2011-02-23        kinaba: 	int B = 44;
4fd800b3a8 2011-02-23        kinaba: 	int K = 50;
4fd800b3a8 2011-02-23        kinaba: 	int _ = -1;
4fd800b3a8 2011-02-23        kinaba: END
4fd800b3a8 2011-02-23        kinaba: CASE(7)
4fd800b3a8 2011-02-23        kinaba: 	int A = 11;
4fd800b3a8 2011-02-23        kinaba: 	int B = 99995;
4fd800b3a8 2011-02-23        kinaba: 	int K = 99999;
4fd800b3a8 2011-02-23        kinaba: 	int _ = 14285;
4fd800b3a8 2011-02-23        kinaba: END
4fd800b3a8 2011-02-23        kinaba: CASE(8)
4fd800b3a8 2011-02-23        kinaba: 	int A = 100000;
4fd800b3a8 2011-02-23        kinaba: 	int B = 100000;
4fd800b3a8 2011-02-23        kinaba: 	int K = 15781;
4fd800b3a8 2011-02-23        kinaba: 	int _ = 8;
4fd800b3a8 2011-02-23        kinaba: END
4fd800b3a8 2011-02-23        kinaba: CASE(9)
4fd800b3a8 2011-02-23        kinaba: 	int A = 7;
4fd800b3a8 2011-02-23        kinaba: 	int B = 99128;
4fd800b3a8 2011-02-23        kinaba: 	int K = 70613;
4fd800b3a8 2011-02-23        kinaba: 	int _ = 5;
4fd800b3a8 2011-02-23        kinaba: END
4fd800b3a8 2011-02-23        kinaba: CASE(10)
4fd800b3a8 2011-02-23        kinaba: 	int A = 45903;
4fd800b3a8 2011-02-23        kinaba: 	int B = 89257;
4fd800b3a8 2011-02-23        kinaba: 	int K = 98937;
4fd800b3a8 2011-02-23        kinaba: 	int _ = 3;
4fd800b3a8 2011-02-23        kinaba: END
4fd800b3a8 2011-02-23        kinaba: CASE(11)
4fd800b3a8 2011-02-23        kinaba: 	int A = 93851;
4fd800b3a8 2011-02-23        kinaba: 	int B = 72517;
4fd800b3a8 2011-02-23        kinaba: 	int K = 16031;
4fd800b3a8 2011-02-23        kinaba: 	int _ = 7;
4fd800b3a8 2011-02-23        kinaba: END
4fd800b3a8 2011-02-23        kinaba: 
4fd800b3a8 2011-02-23        kinaba: }
4fd800b3a8 2011-02-23        kinaba: // END CUT HERE