ADDED   SRM/553-U/1A.cpp
Index: SRM/553-U/1A.cpp
==================================================================
--- SRM/553-U/1A.cpp
+++ SRM/553-U/1A.cpp
@@ -0,0 +1,132 @@
+#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>
+using namespace std;
+typedef long long LL;
+typedef long double LD;
+typedef complex<LD> CMP;
+
+class Suminator { public:
+	int findMissing(vector <int> program, int wantedResult)
+	{
+		set<int> cand;
+
+		int it = find(program.begin(), program.end(), -1) - program.begin();
+		program[it] = 0;
+		if( eval(program) == complex<LL>(wantedResult, 0) )
+			cand.insert(0);
+		program[it] = -1;
+
+		complex<LL> r = eval(program);
+		if( r.imag()==0 ) {
+			if( r.real()==wantedResult )
+				cand.insert(1);
+		} else {
+			// r.real() + r.imag()*modify == wantedResult
+			if( wantedResult > r.real() )
+				if( (wantedResult - r.real()) % r.imag() == 0 )
+					cand.insert(int((wantedResult - r.real())/r.imag()));
+		}
+
+		return cand.empty() ? -1 : *cand.begin();
+	}
+
+	complex<LL> eval(const vector<int>& p)
+	{
+		stack< complex<LL> > stk;
+		for(int i=0; i<p.size(); ++i)
+			if(p[i] == -1)
+				stk.push(complex<LL>(0,1));
+			else if(p[i] != 0)
+				stk.push(complex<LL>(p[i],0));
+			else {
+				complex<LL> a = 0; if(!stk.empty()){ a=stk.top(); stk.pop(); }
+				complex<LL> b = 0; if(!stk.empty()){ b=stk.top(); stk.pop(); }
+				stk.push(a+b);
+			}
+		complex<LL> r = 0; if(!stk.empty()){ r=stk.top(); stk.pop(); }
+		return r;
+	}
+};
+
+// 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(_, Suminator().findMissing(program, wantedResult));}
+int main(){
+
+CASE(0)
+	int program_[] = {7,-1,0};
+	  vector <int> program(program_, program_+sizeof(program_)/sizeof(*program_)); 
+	int wantedResult = 10; 
+	int _ = 3; 
+END
+CASE(1)
+	int program_[] = {100, 200, 300, 0, 100, -1};
+	  vector <int> program(program_, program_+sizeof(program_)/sizeof(*program_)); 
+	int wantedResult = 600; 
+	int _ = 0; 
+END
+CASE(2)
+	int program_[] = {-1, 7, 3, 0, 1, 2, 0, 0};
+	  vector <int> program(program_, program_+sizeof(program_)/sizeof(*program_)); 
+	int wantedResult = 13; 
+	int _ = 0; 
+END
+CASE(3)
+	int program_[] = {-1, 8, 4, 0, 1, 2, 0, 0};
+	  vector <int> program(program_, program_+sizeof(program_)/sizeof(*program_)); 
+	int wantedResult = 16; 
+	int _ = -1; 
+END
+CASE(4)
+	int program_[] = {1000000000, 1000000000, 1000000000,  1000000000, -1, 0, 0, 0, 0};
+	  vector <int> program(program_, program_+sizeof(program_)/sizeof(*program_)); 
+	int wantedResult = 1000000000; 
+	int _ = -1; 
+END
+CASE(5)
+	int program_[] = {7, -1, 3, 0};
+	  vector <int> program(program_, program_+sizeof(program_)/sizeof(*program_)); 
+	int wantedResult = 3; 
+	int _ = -1; 
+END
+/*
+CASE(6)
+	int program_[] = ;
+	  vector <int> program(program_, program_+sizeof(program_)/sizeof(*program_)); 
+	int wantedResult = ; 
+	int _ = ; 
+END
+CASE(7)
+	int program_[] = ;
+	  vector <int> program(program_, program_+sizeof(program_)/sizeof(*program_)); 
+	int wantedResult = ; 
+	int _ = ; 
+END
+*/
+}
+// END CUT HERE

ADDED   SRM/553-U/2A.cpp
Index: SRM/553-U/2A.cpp
==================================================================
--- SRM/553-U/2A.cpp
+++ SRM/553-U/2A.cpp
@@ -0,0 +1,99 @@
+#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>
+using namespace std;
+typedef long long LL;
+typedef long double LD;
+typedef complex<LD> CMP;
+
+class PlatypusDuckAndBeaver { public:
+	int minimumAnimals(int webbedFeet, int duckBills, int beaverTails)
+	{
+		// 2 1 0
+		// 4 0 1
+		// 4 1 1
+		for(int c=0 ;; ++c)
+		{
+			int a = duckBills - c;
+			int b = beaverTails - c;
+			if(a*2+b*4+c*4 == webbedFeet)
+				return a+b+c;
+		}
+	}
+};
+
+// 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(_, PlatypusDuckAndBeaver().minimumAnimals(webbedFeet, duckBills, beaverTails));}
+int main(){
+
+CASE(0)
+	int webbedFeet = 4; 
+	int duckBills = 1; 
+	int beaverTails = 1; 
+	int _ = 1; 
+END
+CASE(1)
+	int webbedFeet = 0; 
+	int duckBills = 0; 
+	int beaverTails = 0; 
+	int _ = 0; 
+END
+CASE(2)
+	int webbedFeet = 10; 
+	int duckBills = 2; 
+	int beaverTails = 2; 
+	int _ = 3; 
+END
+CASE(3)
+	int webbedFeet = 60; 
+	int duckBills = 10; 
+	int beaverTails = 10; 
+	int _ = 20; 
+END
+CASE(4)
+	int webbedFeet = 1000; 
+	int duckBills = 200; 
+	int beaverTails = 200; 
+	int _ = 300; 
+END
+/*
+CASE(5)
+	int webbedFeet = ; 
+	int duckBills = ; 
+	int beaverTails = ; 
+	int _ = ; 
+END
+CASE(6)
+	int webbedFeet = ; 
+	int duckBills = ; 
+	int beaverTails = ; 
+	int _ = ; 
+END
+*/
+}
+// END CUT HERE

ADDED   SRM/553-U/2C.cpp
Index: SRM/553-U/2C.cpp
==================================================================
--- SRM/553-U/2C.cpp
+++ SRM/553-U/2C.cpp
@@ -0,0 +1,120 @@
+#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>
+using namespace std;
+typedef long long LL;
+typedef long double LD;
+typedef complex<LD> CMP;
+
+class SafeRemoval { public:
+	int removeThem(vector <int> seq, int K)
+	{
+		sort(seq.begin(), seq.end());
+		const int sum = accumulate(seq.begin(), seq.end(), 0);
+
+		vector<int> cls[4];
+		for(int i=0; i<seq.size(); ++i)
+			cls[seq[i]%4].push_back(seq[i]);
+
+		int best = -1;
+		for(int r=0; r<4; ++r) {
+			int b = rec(cls, 0, 0, 0, 0, K, sum%4);
+			if(b != -1)
+				best = max(best, sum-b);
+		}
+		return best;
+	}
+
+	map<int, int> memo;
+	int rec(const vector<int> cls[4], int a, int b, int c, int d, int K, int R)
+	{
+		if(K==0)
+			return (R==0 ? -1 : 0);
+		const int key = ((((K*51+a)*51+b)*51+c)*51+d)*4+R;
+		if(memo.count(key))
+			return memo[key];
+
+		int i[4] = {a,b,c,d};
+		int best = -1;
+		for(int k=0; k<4; ++k) if(R!=k && i[k]<cls[k].size()) {
+			i[k]++;
+			int b = rec(cls, i[0], i[1], i[2], i[3], K-1, (R-k+4)%4);
+			i[k]--;
+			if(b != -1) {
+				b += cls[k][i[k]];
+				best = (best==-1 ? b : min(best, b));
+			}
+		}
+		return memo[key] = best;
+	}
+};
+
+// 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(_, SafeRemoval().removeThem(seq, k));}
+int main(){
+
+CASE(0)
+	int seq_[] = {3, 8, 4};
+	  vector <int> seq(seq_, seq_+sizeof(seq_)/sizeof(*seq_)); 
+	int k = 1; 
+	int _ = 11; 
+END
+CASE(1)
+	int seq_[] = {1,1,1,1,1,1};
+	  vector <int> seq(seq_, seq_+sizeof(seq_)/sizeof(*seq_)); 
+	int k = 3; 
+	int _ = -1; 
+END
+CASE(2)
+	int seq_[] = {1,6,1,10,1,2,7,11};
+	  vector <int> seq(seq_, seq_+sizeof(seq_)/sizeof(*seq_)); 
+	int k = 6; 
+	int _ = 21; 
+END
+CASE(3)
+	int seq_[] = {1,1,1,1,1,1,1,1,7};
+	  vector <int> seq(seq_, seq_+sizeof(seq_)/sizeof(*seq_)); 
+	int k = 3; 
+	int _ = 6; 
+END
+/*
+CASE(4)
+	int seq_[] = ;
+	  vector <int> seq(seq_, seq_+sizeof(seq_)/sizeof(*seq_)); 
+	int k = ; 
+	int _ = ; 
+END
+CASE(5)
+	int seq_[] = ;
+	  vector <int> seq(seq_, seq_+sizeof(seq_)/sizeof(*seq_)); 
+	int k = ; 
+	int _ = ; 
+END
+*/
+}
+// END CUT HERE