ADDED   SRM/428/2A.cpp
Index: SRM/428/2A.cpp
==================================================================
--- SRM/428/2A.cpp
+++ SRM/428/2A.cpp
@@ -0,0 +1,85 @@
+#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 ThePalindrome { public:
+	int find(string s)
+	{
+		for(int i=0; i<s.size(); ++i)
+			if( is_palin(s + string(s.rbegin()+(s.size()-i), s.rend())) )
+				return i + s.size();
+		return s.size() * 2;
+	}
+
+	bool is_palin(const string& s) {
+		return s == string(s.rbegin(), s.rend());
+	}
+};
+
+// 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(_, ThePalindrome().find(s));}
+int main(){
+
+CASE(0)
+	string s = "abab"; 
+	int _ = 5; 
+END
+CASE(1)
+	string s = "abacaba"; 
+	int _ = 7; 
+END
+CASE(2)
+	string s = "qwerty"; 
+	int _ = 11; 
+END
+CASE(3)
+	string s = "abdfhdyrbdbsdfghjkllkjhgfds"; 
+	int _ = 38; 
+END
+/*
+CASE(4)
+	string s = ; 
+	int _ = ; 
+END
+CASE(5)
+	string s = ; 
+	int _ = ; 
+END
+*/
+}
+// END CUT HERE

ADDED   SRM/428/2C.cpp
Index: SRM/428/2C.cpp
==================================================================
--- SRM/428/2C.cpp
+++ SRM/428/2C.cpp
@@ -0,0 +1,119 @@
+#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 TheDictionary { public:
+	string find(int n, int m, int k)
+	{
+		if( k <= C(n+m,n) )
+			return rec(n, m, k);
+		return "";
+	}
+
+	string rec(int n, int m, int k)
+	{
+		if( n+m == 0 )
+			return "";
+		if( n==0 )
+			return "z" + rec(n, m-1, k);
+		if( m==0 )
+			return "a" + rec(n-1, m, k);
+
+		LL c = C(n+m-1, m);
+		if( k <= c )
+			return "a" + rec(n-1, m, k);
+		return "z" + rec(n, m-1, k - c);
+	}
+
+	LL C(int n, int k)
+	{
+		k = min(k, n-k);
+		LL v = 1;
+		for(int i=1; i<=k; ++i) {
+			v = v * (n+1-i) / i;
+			if( v >= (1LL<<50) )
+				return v;
+		}
+		return v;
+	}
+};
+
+// 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(_, TheDictionary().find(n, m, k));}
+int main(){
+
+CASE(0)
+	int n = 2; 
+	int m = 2; 
+	int k = 2; 
+	string _ = "azaz"; 
+END
+CASE(1)
+	int n = 2; 
+	int m = 2; 
+	int k = 6; 
+	string _ = "zzaa"; 
+END
+CASE(2)
+	int n = 10; 
+	int m = 10; 
+	int k = 1000000000; 
+	string _ = ""; 
+END
+CASE(3)
+	int n = 7; 
+	int m = 4; 
+	int k = 47; 
+	string _ = "aaazazaazaz"; 
+END
+/*
+CASE(4)
+	int n = ; 
+	int m = ; 
+	int k = ; 
+	string _ = ; 
+END
+CASE(5)
+	int n = ; 
+	int m = ; 
+	int k = ; 
+	string _ = ; 
+END
+*/
+}
+// END CUT HERE