ADDED   SRM/537-U/1A.cpp
Index: SRM/537-U/1A.cpp
==================================================================
--- SRM/537-U/1A.cpp
+++ SRM/537-U/1A.cpp
@@ -0,0 +1,115 @@
+#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 <cstring>
+#ifdef __GNUC__
+#include <ext/hash_map>
+#define unordered_map __gnu_cxx::hash_map
+#else
+#include <unordered_map>
+#endif
+using namespace std;
+typedef long long LL;
+typedef complex<double> CMP;
+
+class KingXNewCurrency { public:
+	int howMany(int A, int B, int X)
+	{
+		if(A%X==0 && B%X==0)
+			return -1;
+		int cnt = 0;
+		for(int Y=1; Y<=max(A,B); ++Y)
+			if( possible(A,B,X,Y) )
+				cnt++;
+		return cnt;
+	}
+
+	bool possible(int A, int B, int X, int Y)
+	{
+		bool Aok = false;
+		for(int p=0; p*X<=A; ++p)
+			if( (A-p*X)%Y == 0 )
+				Aok = true;
+		bool Bok = false;
+		for(int p=0; p*X<=B; ++p)
+			if( (B-p*X)%Y == 0 )
+				Bok = true;
+		return Aok&&Bok;
+	}
+};
+
+// 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(_, KingXNewCurrency().howMany(A, B, X));}
+int main(){
+
+CASE(0)
+	int A = 5; 
+	int B = 8; 
+	int X = 5; 
+	int _ = 5; 
+END
+CASE(1)
+	int A = 8; 
+	int B = 4; 
+	int X = 2; 
+	int _ = -1; 
+END
+CASE(2)
+	int A = 7; 
+	int B = 4; 
+	int X = 13; 
+	int _ = 1; 
+END
+CASE(3)
+	int A = 47; 
+	int B = 74; 
+	int X = 44; 
+	int _ = 2; 
+END
+CASE(4)
+	int A = 128; 
+	int B = 96; 
+	int X = 3; 
+	int _ = 65; 
+END
+/*
+CASE(5)
+	int A = ; 
+	int B = ; 
+	int X = ; 
+	int _ = ; 
+END
+CASE(6)
+	int A = ; 
+	int B = ; 
+	int X = ; 
+	int _ = ; 
+END
+*/
+}
+// END CUT HERE

ADDED   SRM/537-U/1B.cpp
Index: SRM/537-U/1B.cpp
==================================================================
--- SRM/537-U/1B.cpp
+++ SRM/537-U/1B.cpp
@@ -0,0 +1,151 @@
+#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 <cstring>
+#ifdef __GNUC__
+#include <ext/hash_map>
+#define unordered_map __gnu_cxx::hash_map
+#else
+#include <unordered_map>
+#endif
+using namespace std;
+typedef long long LL;
+typedef complex<double> CMP;
+
+class KingXMagicSpells { public:
+	double expectedNumber(vector <int> ducks, vector <int> spellOne, vector <int> spellTwo, int K)
+	{
+		const int N = ducks.size();
+
+		vector<int> revSpellTwo(N);
+		for(int i=0; i<N; ++i) revSpellTwo[spellTwo[i]] = i;
+
+		double e = 0;
+		for(int B=30; B>=0; --B) {
+			vector<int> dd(N);
+			for(int i=0; i<N; ++i)
+				dd[i] = (ducks[i] & (1<<B) ? 1 : 0);
+			vector<int> xx(N);
+			for(int i=0; i<N; ++i)
+				xx[i] = (spellOne[i] & (1<<B) ? 1 : 0);
+			e += solve(dd, xx, revSpellTwo, K) * (1<<B);
+		}
+		return e;
+	}
+
+	double solve(const vector <int>& dd, const vector <int>& xx, const vector <int>& moveBack, int K)
+	{
+		memo.clear();
+		return prob(dd, xx, moveBack, K, 0, 1);
+	}
+
+	map<int, double> memo;
+	double prob(
+		const vector <int>& dd, const vector <int>& xx, const vector <int>& moveBack,
+		int K, int room, int bit) {
+		if( K == 0 ) {
+			return dd[room]==bit ? 1.0 : 0.0;
+		}
+
+		int key = (K * 100 + room) * 2 + bit;
+		if( memo.count(key) )
+			return memo[key];
+		double e = 0.5 * prob(dd,xx,moveBack,K-1,moveBack[room],bit)
+		         + 0.5 * prob(dd,xx,moveBack,K-1,room,bit^xx[room]);
+		return memo[key] = e;
+	}
+};
+
+// 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 double& Expected, const double& Received) {
+ bool ok = (abs(Expected - Received) < 1e-9);
+ 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(_, KingXMagicSpells().expectedNumber(ducks, spellOne, spellTwo, K));}
+int main(){
+
+CASE(0)
+	int ducks_[] = {5, 3, 7};
+	  vector <int> ducks(ducks_, ducks_+sizeof(ducks_)/sizeof(*ducks_)); 
+	int spellOne_[] = {1, 7, 4};
+	  vector <int> spellOne(spellOne_, spellOne_+sizeof(spellOne_)/sizeof(*spellOne_)); 
+	int spellTwo_[] = {1, 0, 2};
+	  vector <int> spellTwo(spellTwo_, spellTwo_+sizeof(spellTwo_)/sizeof(*spellTwo_)); 
+	int K = 1; 
+	double _ = 3.5; 
+END
+CASE(1)
+	int ducks_[] = {5, 8};
+	  vector <int> ducks(ducks_, ducks_+sizeof(ducks_)/sizeof(*ducks_)); 
+	int spellOne_[] = {53, 7};
+	  vector <int> spellOne(spellOne_, spellOne_+sizeof(spellOne_)/sizeof(*spellOne_)); 
+	int spellTwo_[] = {1, 0};
+	  vector <int> spellTwo(spellTwo_, spellTwo_+sizeof(spellTwo_)/sizeof(*spellTwo_)); 
+	int K = 2; 
+	double _ = 21.5; 
+END
+CASE(2)
+	int ducks_[] = {123, 456, 789, 1234, 56789};
+	  vector <int> ducks(ducks_, ducks_+sizeof(ducks_)/sizeof(*ducks_)); 
+	int spellOne_[] = {0, 0, 0, 0, 0};
+	  vector <int> spellOne(spellOne_, spellOne_+sizeof(spellOne_)/sizeof(*spellOne_)); 
+	int spellTwo_[] = {0, 1, 2, 3, 4};
+	  vector <int> spellTwo(spellTwo_, spellTwo_+sizeof(spellTwo_)/sizeof(*spellTwo_)); 
+	int K = 50; 
+	double _ = 123.0; 
+END
+CASE(3)
+	int ducks_[] = {83291232, 3124231, 192412, 3813249, 629231, 9998989};
+	  vector <int> ducks(ducks_, ducks_+sizeof(ducks_)/sizeof(*ducks_)); 
+	int spellOne_[] = {58, 37, 44, 66, 72, 19};
+	  vector <int> spellOne(spellOne_, spellOne_+sizeof(spellOne_)/sizeof(*spellOne_)); 
+	int spellTwo_[] = {2, 0, 1, 5, 4, 3};
+	  vector <int> spellTwo(spellTwo_, spellTwo_+sizeof(spellTwo_)/sizeof(*spellTwo_)); 
+	int K = 11; 
+	double _ = 2.888186784716797E7; 
+END
+/*
+CASE(4)
+	int ducks_[] = ;
+	  vector <int> ducks(ducks_, ducks_+sizeof(ducks_)/sizeof(*ducks_)); 
+	int spellOne_[] = ;
+	  vector <int> spellOne(spellOne_, spellOne_+sizeof(spellOne_)/sizeof(*spellOne_)); 
+	int spellTwo_[] = ;
+	  vector <int> spellTwo(spellTwo_, spellTwo_+sizeof(spellTwo_)/sizeof(*spellTwo_)); 
+	int K = ; 
+	double _ = ; 
+END
+CASE(5)
+	int ducks_[] = ;
+	  vector <int> ducks(ducks_, ducks_+sizeof(ducks_)/sizeof(*ducks_)); 
+	int spellOne_[] = ;
+	  vector <int> spellOne(spellOne_, spellOne_+sizeof(spellOne_)/sizeof(*spellOne_)); 
+	int spellTwo_[] = ;
+	  vector <int> spellTwo(spellTwo_, spellTwo_+sizeof(spellTwo_)/sizeof(*spellTwo_)); 
+	int K = ; 
+	double _ = ; 
+END
+*/
+}
+// END CUT HERE