ADDED   SRM/620-U/1A-U.cpp
Index: SRM/620-U/1A-U.cpp
==================================================================
--- SRM/620-U/1A-U.cpp
+++ SRM/620-U/1A-U.cpp
@@ -0,0 +1,124 @@
+#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 PairGame { public:
+	int maxSum(int a, int b, int c, int d)
+	{
+		vector<pair<int,int>> s1 = seq(a,b);
+		vector<pair<int,int>> s2 = seq(c,d);
+		int cand = -1;
+		for(auto& p1: s1)
+		for(auto& p2: s2)
+			if(p1 == p2)
+				cand = max(cand, p1.first + p1.second);
+		return cand;
+	}
+
+	vector<pair<int,int>> seq(int a, int b)
+	{
+		vector<pair<int,int>> s;
+		do {
+			s.emplace_back(a, b);
+			if(a<b)
+				b-=a;
+			else
+				a-=b;
+		} while(a && b);
+		return s;
+	}
+};
+
+// 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(_, PairGame().maxSum(a, b, c, d));}
+int main(){
+
+CASE(0)
+	int a = 1; 
+	int b = 2; 
+	int c = 2; 
+	int d = 1; 
+	int _ = 2; 
+END
+CASE(1)
+	int a = 15; 
+	int b = 4; 
+	int c = 10; 
+	int d = 7; 
+	int _ = 7; 
+END
+CASE(2)
+	int a = 1; 
+	int b = 1; 
+	int c = 10; 
+	int d = 10; 
+	int _ = -1; 
+END
+CASE(3)
+	int a = 1000; 
+	int b = 1001; 
+	int c = 2000; 
+	int d = 2001; 
+	int _ = 1001; 
+END
+CASE(4)
+	int a = 10944; 
+	int b = 17928; 
+	int c = 7704; 
+	int d = 21888; 
+	int _ = 144; 
+END
+CASE(5)
+	int a = 1; 
+	int b = 1; 
+	int c = 1; 
+	int d = 1; 
+	int _ = 2; 
+END
+/*
+CASE(6)
+	int a = ; 
+	int b = ; 
+	int c = ; 
+	int d = ; 
+	int _ = ; 
+END
+CASE(7)
+	int a = ; 
+	int b = ; 
+	int c = ; 
+	int d = ; 
+	int _ = ; 
+END
+*/
+}
+// END CUT HERE

ADDED   SRM/620-U/1B.cpp
Index: SRM/620-U/1B.cpp
==================================================================
--- SRM/620-U/1B.cpp
+++ SRM/620-U/1B.cpp
@@ -0,0 +1,159 @@
+#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 CandidatesSelection { public:
+	string possible(vector <string> score, vector <int> result)
+	{
+		return solve(score, result) ? "Possible" : "Impossible";
+	}
+
+	bool solve(vector <string> score, vector <int> result)
+	{
+		const int N = score.size();
+		const int S = score[0].size();
+
+		// po[a][b] : bitmask of skill set that makes a<b.
+		vector<vector<LL>> po(N, vector<LL>(N));
+		for(int a=0; a<N; ++a)
+		for(int b=0; b<N; ++b) if(a!=b)
+		{
+			LL mask = 0;
+			for(int s=0; s<S; ++s)
+				if(score[a][s] <= score[b][s])
+					mask |= 1LL<<s;
+			if(a<b)
+				mask |= 1LL<<S;
+			po[a][b] = mask;
+		}
+
+		vector<vector<int>> now(1, result);
+
+		function<bool(LL,vector<vector<int>>)> rec;
+		rec = [&](LL used, vector<vector<int>> obl) {
+			LL pos = ~0LL;
+			for(auto& oi: obl)
+				for(int i=0; i+1<oi.size(); ++i)
+					pos &= po[oi[i]][oi[i+1]];
+			if(pos & (1LL<<S)) // original order is enough.
+				return true;
+
+			bool changed = false;
+			for(int s=0; s<S; ++s) if(pos & ~used & (1LL<<s)) {
+				vector<vector<int>> next;
+				for(auto& oi: obl) {
+					vector<int> cur;
+					for(int o: oi) {
+						if(!cur.empty() && score[cur.back()][s] < score[o][s]) {
+							changed = true;
+							if(cur.size()>=2)
+								next.push_back(cur);
+							cur.clear();
+						}
+						cur.push_back(o);
+					}
+					if(cur.size()>=2)
+						next.push_back(cur);
+				}
+				obl = std::move(next);
+			}
+			return changed && rec(used|pos, obl);
+		};
+		return rec(0, now);
+	}
+
+};
+
+// 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(_, CandidatesSelection().possible(score, result));}
+int main(){
+
+CASE(0)
+	string score_[] = {"CC", "AA", "BB"};
+	  vector <string> score(score_, score_+sizeof(score_)/sizeof(*score_)); 
+	int result_[] = {1,2,0};
+	  vector <int> result(result_, result_+sizeof(result_)/sizeof(*result_)); 
+	string _ = "Possible"; 
+END
+CASE(1)
+	string score_[] = {"BAB", "ABB", "AAB", "ABA"};
+	  vector <string> score(score_, score_+sizeof(score_)/sizeof(*score_)); 
+	int result_[] = {2,0,1,3};
+	  vector <int> result(result_, result_+sizeof(result_)/sizeof(*result_)); 
+	string _ = "Possible"; 
+END
+CASE(2)
+	string score_[] = {"BAB", "ABB", "AAB", "ABA"};
+	  vector <string> score(score_, score_+sizeof(score_)/sizeof(*score_)); 
+	int result_[] = {0, 1, 3, 2};
+	  vector <int> result(result_, result_+sizeof(result_)/sizeof(*result_)); 
+	string _ = "Impossible"; 
+END
+CASE(3)
+	string score_[] = {"AAA", "ZZZ"};
+	  vector <string> score(score_, score_+sizeof(score_)/sizeof(*score_)); 
+	int result_[] = {1, 0};
+	  vector <int> result(result_, result_+sizeof(result_)/sizeof(*result_)); 
+	string _ = "Impossible"; 
+END
+CASE(4)
+	string score_[] = {"ZZZ", "AAA"};
+	  vector <string> score(score_, score_+sizeof(score_)/sizeof(*score_)); 
+	int result_[] = {0, 1};
+	  vector <int> result(result_, result_+sizeof(result_)/sizeof(*result_)); 
+	string _ = "Possible"; 
+END
+CASE(5)
+	string score_[] = {"ZYYYYX","YXZYXY","ZZZZXX","XZXYYX","ZZZYYZ","ZZXXYZ","ZYZZXZ","XZYYZX"};
+	  vector <string> score(score_, score_+sizeof(score_)/sizeof(*score_)); 
+	int result_[] = {3,7,1,0,2,5,6,4};
+	  vector <int> result(result_, result_+sizeof(result_)/sizeof(*result_)); 
+	string _ = "Possible"; 
+END
+/*
+CASE(6)
+	string score_[] = ;
+	  vector <string> score(score_, score_+sizeof(score_)/sizeof(*score_)); 
+	int result_[] = ;
+	  vector <int> result(result_, result_+sizeof(result_)/sizeof(*result_)); 
+	string _ = ; 
+END
+CASE(7)
+	string score_[] = ;
+	  vector <string> score(score_, score_+sizeof(score_)/sizeof(*score_)); 
+	int result_[] = ;
+	  vector <int> result(result_, result_+sizeof(result_)/sizeof(*result_)); 
+	string _ = ; 
+END
+*/
+}
+// END CUT HERE