ADDED   SRM/604-U/1A.cpp
Index: SRM/604-U/1A.cpp
==================================================================
--- SRM/604-U/1A.cpp
+++ SRM/604-U/1A.cpp
@@ -0,0 +1,111 @@
+#include <iostream>
+#include <sstream>
+#include <iomanip>
+#include <vector>
+#include <string>
+#include <map>
+#include <set>
+#include <algorithm>
+#include <numeric>
+#include <iterator>
+#include <functional>
+#include <complex>
+#include <queue>
+#include <stack>
+#include <cmath>
+#include <cassert>
+#include <tuple>
+using namespace std;
+typedef long long LL;
+typedef complex<double> CMP;
+
+class PowerOfThree { public:
+	string ableToGet(int x_, int y_)
+	{
+		LL x=x_, y=y_;
+		for(LL tk=1;; tk*=3)
+		{
+			if(x==0 && y==0)
+				break;
+			LL xr = ((x/tk)%3+3)%3;
+			LL yr = ((y/tk)%3+3)%3;
+			if(xr==1 && yr==0) x-=tk;
+			else if(xr==2 && yr==0) x+=tk;
+			else if(xr==0 && yr==1) y-=tk;
+			else if(xr==0 && yr==2) y+=tk;
+			else return "Impossible";
+		}
+		return "Possible";
+	}
+};
+
+// BEGIN CUT HERE
+#include <ctime>
+double start_time; string timer()
+ { ostringstream os; os << " (" << int((clock()-start_time)/CLOCKS_PER_SEC*1000) << " msec)"; return os.str(); }
+template<typename T> ostream& operator<<(ostream& os, const vector<T>& v)
+ { os << "{ ";
+   for(typename vector<T>::const_iterator it=v.begin(); it!=v.end(); ++it)
+   os << '\"' << *it << '\"' << (it+1==v.end() ? "" : ", "); os << " }"; return os; }
+void verify_case(const string& Expected, const string& Received) {
+ bool ok = (Expected == Received);
+ if(ok) cerr << "PASSED" << timer() << endl;  else { cerr << "FAILED" << timer() << endl;
+ cerr << "\to: \"" << Expected << '\"' << endl << "\tx: \"" << Received << '\"' << endl; } }
+#define CASE(N) {cerr << "Test Case #" << N << "..." << flush; start_time=clock();
+#define END	 verify_case(_, PowerOfThree().ableToGet(x, y));}
+int main(){
+
+CASE(0)
+	int x = 1; 
+	int y = 3; 
+	string _ = "Possible"; 
+END
+CASE(1)
+	int x = 0; 
+	int y = 2; 
+	string _ = "Possible"; 
+END
+CASE(2)
+	int x = 1; 
+	int y = 9; 
+	string _ = "Impossible"; 
+END
+CASE(3)
+	int x = 3; 
+	int y = 0; 
+	string _ = "Impossible"; 
+END
+CASE(4)
+	int x = 1; 
+	int y = 1; 
+	string _ = "Impossible"; 
+END
+CASE(5)
+	int x = -6890; 
+	int y = 18252; 
+	string _ = "Possible"; 
+END
+CASE(6)
+	int x = 1000000000; 
+	int y = -1000000000; 
+	string _ = "Impossible"; 
+END
+CASE(7)
+	int x = 0; 
+	int y = 0; 
+	string _ = "Possible"; 
+END
+CASE(8)
+	int x = 8; 
+	int y = 3; 
+	string _ = "P"; 
+END
+CASE(9)
+	// -3^0 - 3^1 - ... - 3^18 + 3^19
+	// NOTE: 3^19 = 1162261467 > 10^9
+	int x = 581130734;
+	int y = 0; 
+	string _ = "P"; 
+END
+}
+// END CUT HERE

ADDED   SRM/604-U/1B-U.cpp
Index: SRM/604-U/1B-U.cpp
==================================================================
--- SRM/604-U/1B-U.cpp
+++ SRM/604-U/1B-U.cpp
@@ -0,0 +1,200 @@
+#include <iostream>
+#include <sstream>
+#include <iomanip>
+#include <vector>
+#include <string>
+#include <map>
+#include <set>
+#include <algorithm>
+#include <numeric>
+#include <iterator>
+#include <functional>
+#include <complex>
+#include <queue>
+#include <stack>
+#include <cmath>
+#include <cassert>
+#include <tuple>
+using namespace std;
+typedef long long LL;
+typedef complex<double> CMP;
+
+template<typename T>
+struct DP2
+{
+	const int N1, N2;
+	vector<T> data;
+	DP2(int N1, int N2, const T& t = T())
+		: N1(N1), N2(N2), data(N1*N2, t) { assert(data.size()*sizeof(T)<(1<<28)); }
+	T& operator()(int i1, int i2)
+		{ return data[ (i1*N2)+i2 ]; }
+	void swap(DP2& rhs)
+		{ data.swap(rhs.data); }
+};
+
+static const int INF = 0x3fffffff;
+class FoxConnection { public:
+	int minimalDistance(vector <int> A, vector <int> B, string haveFox)
+	{
+		int N = haveFox.size();
+		vector<vector<int>> G(N);
+		for(int i=0; i<A.size(); ++i) {
+			int a = A[i] - 1;
+			int b = B[i] - 1;
+			G[a].push_back(b);
+			G[b].push_back(a);
+		}
+
+		int best = INF;
+		memo.resize(N+1, vector<vector<int>>(N));
+		ts_memo.resize(N+1, vector<int>(N, INF));
+		for(int root=0; root<N; ++root) {
+			const vector<int>& L = rec(-1, root, G, haveFox);
+			best = min(best, L[0]);
+		}
+		return best==INF ? 0 : best;
+	}
+
+	vector<vector<int>> ts_memo;
+	int treeSize(int prev, int v, const vector<vector<int>>& G, const string& haveFox)
+	{
+		if(ts_memo[prev+1][v] != INF)
+			return ts_memo[prev+1][v];
+
+		int ts = (haveFox[v]=='Y');
+		for(int u : G[v]) if(u != prev)
+			ts += treeSize(v, u, G, haveFox);
+		return ts_memo[prev+1][v] = ts;
+	}
+
+	vector<vector<vector<int>>> memo;
+	const vector<int>& rec(int prev, int v, const vector<vector<int>>& G, const string& haveFox)
+	{
+		if(!memo[prev+1][v].empty())
+			return memo[prev+1][v];
+		int N = G.size();
+
+		vector<const vector<int>*> children;
+		for(int u : G[v]) if(u != prev)
+			children.push_back(&rec(v,u,G,haveFox));
+		int Z = children.size();
+
+		DP2<int> dp(Z+1, N, INF);
+		dp(0,0) = 0;
+		for(int i=0; i<Z; ++i)
+		{
+			const vector<int>& ch = *children[i];
+			for(int t=0; t<N; ++t)
+			for(int w=0; w<N; ++w)
+				if(t+w<N)
+					dp(i+1, t+w) = min(dp(i+1, t+w), dp(i,t)+ch[w]);
+		}
+
+		const bool Y = (haveFox[v]=='Y');
+		vector<int>& L = memo[prev+1][v];
+		L.resize(N, INF);
+
+		const int TS = treeSize(prev, v, G, haveFox);
+		for(int i=0; i<N; ++i)
+		{
+			if(i == TS)
+				L[i] = min(INF, TS + (Y ? dp(Z,TS-1) : dp(Z,TS)));
+			else
+				L[i] = min(INF, i + (Y ? dp(Z,i) : i+1<N ? dp(Z,i+1) : INF));
+		}
+		return L;
+	}
+};
+
+// BEGIN CUT HERE
+#include <ctime>
+double start_time; string timer()
+ { ostringstream os; os << " (" << int((clock()-start_time)/CLOCKS_PER_SEC*1000) << " msec)"; return os.str(); }
+template<typename T> ostream& operator<<(ostream& os, const vector<T>& v)
+ { os << "{ ";
+   for(typename vector<T>::const_iterator it=v.begin(); it!=v.end(); ++it)
+   os << '\"' << *it << '\"' << (it+1==v.end() ? "" : ", "); os << " }"; return os; }
+void verify_case(const int& Expected, const int& Received) {
+ bool ok = (Expected == Received);
+ if(ok) cerr << "PASSED" << timer() << endl;  else { cerr << "FAILED" << timer() << endl;
+ cerr << "\to: \"" << Expected << '\"' << endl << "\tx: \"" << Received << '\"' << endl; } }
+#define CASE(N) {cerr << "Test Case #" << N << "..." << flush; start_time=clock();
+#define END	 verify_case(_, FoxConnection().minimalDistance(A, B, haveFox));}
+int main(){
+
+CASE(0)
+	int A_[] = {1,2,3};
+	  vector <int> A(A_, A_+sizeof(A_)/sizeof(*A_)); 
+	int B_[] = {2,3,4};
+	  vector <int> B(B_, B_+sizeof(B_)/sizeof(*B_)); 
+	string haveFox = "YNNY"; 
+	int _ = 2; 
+END
+CASE(1)
+	int A_[] = {1,1,1,1};
+	  vector <int> A(A_, A_+sizeof(A_)/sizeof(*A_)); 
+	int B_[] = {2,3,4,5};
+	  vector <int> B(B_, B_+sizeof(B_)/sizeof(*B_)); 
+	string haveFox = "NYYYY"; 
+	int _ = 1; 
+END
+CASE(2)
+	int A_[] = {1,3,4,5,4};
+	  vector <int> A(A_, A_+sizeof(A_)/sizeof(*A_)); 
+	int B_[] = {2,2,2,4,6};
+	  vector <int> B(B_, B_+sizeof(B_)/sizeof(*B_)); 
+	string haveFox = "YNYNYY"; 
+	int _ = 2; 
+END
+CASE(3)
+	int A_[] = {1,2,3,4,5,6,7,8,9};
+	  vector <int> A(A_, A_+sizeof(A_)/sizeof(*A_)); 
+	int B_[] = {2,3,4,5,6,7,8,9,10};
+	  vector <int> B(B_, B_+sizeof(B_)/sizeof(*B_)); 
+	string haveFox = "YNNNYNYNNY"; 
+	int _ = 7; 
+END
+CASE(4)
+	int A_[] = {1,2,3,4,3,6,8,7};
+	  vector <int> A(A_, A_+sizeof(A_)/sizeof(*A_)); 
+	int B_[] = {2,3,4,5,6,8,9,6};
+	  vector <int> B(B_, B_+sizeof(B_)/sizeof(*B_)); 
+	string haveFox = "YNNYYNYYY"; 
+	int _ = 3; 
+END
+CASE(5)
+	int A_[] = {1};
+	  vector <int> A(A_, A_+sizeof(A_)/sizeof(*A_)); 
+	int B_[] = {2};
+	  vector <int> B(B_, B_+sizeof(B_)/sizeof(*B_)); 
+	string haveFox = "NY"; 
+	int _ = 0; 
+END
+CASE(6)
+	int A_[] = {1};
+	  vector <int> A(A_, A_+sizeof(A_)/sizeof(*A_)); 
+	int B_[] = {2};
+	  vector <int> B(B_, B_+sizeof(B_)/sizeof(*B_)); 
+	string haveFox = "NN"; 
+	int _ = 0; 
+END
+/*
+CASE(7)
+	int A_[] = ;
+	  vector <int> A(A_, A_+sizeof(A_)/sizeof(*A_)); 
+	int B_[] = ;
+	  vector <int> B(B_, B_+sizeof(B_)/sizeof(*B_)); 
+	string haveFox = ; 
+	int _ = ; 
+END
+CASE(8)
+	int A_[] = ;
+	  vector <int> A(A_, A_+sizeof(A_)/sizeof(*A_)); 
+	int B_[] = ;
+	  vector <int> B(B_, B_+sizeof(B_)/sizeof(*B_)); 
+	string haveFox = ; 
+	int _ = ; 
+END
+*/
+}
+// END CUT HERE