ADDED   SRM/TCO15-2D-U/1A.cpp
Index: SRM/TCO15-2D-U/1A.cpp
==================================================================
--- SRM/TCO15-2D-U/1A.cpp
+++ SRM/TCO15-2D-U/1A.cpp
@@ -0,0 +1,131 @@
+#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 BalancedSubstrings { public:
+	int countSubstrings(string s)
+	{
+		const int N = s.size();
+
+		int numAllZeroRange = 0;
+		for(int i=0; i<N; ++i)
+			for(int k=i; k<N && s[k]=='0'; ++k)
+				++numAllZeroRange;
+
+		vector<int> leftZero(N), rightZero(N);
+		for(int i=1; i<N; ++i)
+			leftZero[i] = (s[i-1]=='0' ? leftZero[i-1]+1 : 0);
+		for(int i=N-2; i>=0; --i)
+			rightZero[i] = (s[i+1]=='0' ? rightZero[i+1]+1 : 0);
+
+		set<pair<int,int>> OneOneRange;
+		for(int c=0; c<N; ++c) {
+			// take c as the center.
+			// enumerate all balanced [L, R].
+			int L=c, R=c, Lw=0, Rw=0;
+			if(s[L]=='1')
+				OneOneRange.emplace(L,R);
+			while(0<=L && R<N) {
+				const bool moveL = (Lw<Rw || Lw==Rw);
+				const bool moveR = (Lw>Rw || Lw==Rw);
+
+				if(moveL)
+					while(--L>=0)
+						if(s[L]=='1') {
+							Lw += (c-L);
+							break;
+						}
+				if(moveR)
+					while(++R<N)
+						if(s[R]=='1') {
+							Rw += (R-c);
+							break;
+						}
+				if(0<=L && R<N && Lw==Rw)
+					OneOneRange.emplace(L, R);
+			}
+		}
+		int numOtherRange = 0;
+		for(auto lr: OneOneRange) {
+			int L = lr.first, R = lr.second;
+			numOtherRange += (leftZero[L]+1) * (rightZero[R]+1);
+		}
+		return numAllZeroRange + numOtherRange;
+	}
+};
+
+// 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(_, BalancedSubstrings().countSubstrings(s));}
+int main(){
+
+CASE(0)
+	string s = "011"; 
+	int _ = 4; 
+END
+CASE(1)
+	string s = "10111"; 
+	int _ = 10; 
+END
+CASE(2)
+	string s = "00000"; 
+	int _ = 15; 
+END
+CASE(3)
+	string s = "0000001000000"; 
+	int _ = 91; 
+END
+CASE(4)
+	string s = "100110001001"; 
+	int _ = 49; 
+END
+CASE(5)
+	string s = "0"; 
+	int _ = 1; 
+END
+CASE(5)
+	string s = "1"; 
+	int _ = 1; 
+END
+CASE(5)
+	string s = "1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111"; 
+	int _ = 1563750; 
+END
+CASE(5)
+	string s = "0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"; 
+	int _ =	3126250; 
+END
+CASE(5)
+	string s = "1000111010010001011011011010000101101001011001001010101001010100101011011101011111101011011111110001001110010101111010101000001011100011100110101011010001010010110001000111000010110101111101100001000010100010000000101101010011100000000010100010011000101010100100111101001000000000001111011001011101010000011000000110011111011110100101011011111101001111000101011000101110101001001000001101100101000110100111000110100000000011001110110110011011110101101010111010011011101101111110010110101100001101111111101010000010001001001001110111001101110000111001110101111000110011010101010111100001001111110010101010100000010011111010100001101100111111010110010110011010101110110100001100000111000011100100000110111101110010101011101101101100001100111111110011100101101111000011010001000111011001100010100110001010101011101110100100101001000000010000001000001111001110111101110011000111010010101110000111101011010000011000101111011000101110101000011000110010011011001000001001111100110001011110010101000000001110010111100101101111100000001110000011100101001000100011101100011010010100011101111100001010111101000110010111000110101000101100001101111111011000111001110010011010011111100101000000010101110100100101100010001000101001110100001111010100011110000010001011100000100110010111000111110010101110000000110010000111001000010010111011111110110100000101011110000100110101111000111010001001101100000111010101000000011110001101011001010010101001111111010101001011010010011110111110100011000100111010010101111101011010001110001111011000101110101001110111000010100101110001110011110111101111000011100111010100011010100110110010100001100000000000110100001101110001001100011001111001001101011000110011101100010110011001100100111110010011001101111110000011010111111100101000110001111101101011111001011000010101111000110100000000111100100100001010011001100001101010100001101010101100110001100110110111111101000101000000101111010010010101000011101100100010100000111111101001010100000110110110110011110111010010100001100001010001000001000001111001001111110001100010001001101101110110111010011010100101101010111000010100001000000010010010110110110000010100010010101111101101001111101001010000011000010000011000011111010001101101101011100001101010001001011001011000010100101010000111010101111100101010111111111100010111101101110110101110101110100010010010011101010001010011110111010111011010011110111000100111000111100001111011001010010111010101001000110010000010110001011111111000001100001000100001000111000111111011110101"; 
+	int _ = 36497; 
+END
+}
+// END CUT HERE

ADDED   SRM/TCO15-2D-U/1B.cpp
Index: SRM/TCO15-2D-U/1B.cpp
==================================================================
--- SRM/TCO15-2D-U/1B.cpp
+++ SRM/TCO15-2D-U/1B.cpp
@@ -0,0 +1,94 @@
+#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 BallsInBoxes { public:
+	long long maxTurns(long long N, long long K)
+	{
+		if(N < 2*K)
+			return shortCase(N, K);
+		if(N < 3*K)
+			return 1 + shortCase((N+K)/2, K);
+		if(N < 10*K)
+			return 1 + maxTurns(N-K, K);
+		return (N/K-4) + maxTurns(N - (N/K-4)*K, K);
+	}
+
+	LL shortCase(LL N, LL K) {
+		// The case where N is small enough and all positions are possoible.
+		return solve(N-K);
+	}
+
+	LL solve(LL N) {
+		// Determine what number in [0,N] out of N boxes are filled.
+		return N ? solve(N/2)+1 : 0;
+	}
+};
+
+// 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 long long& Expected, const long long& 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(_, BallsInBoxes().maxTurns(N, K));}
+int main(){
+
+CASE(0)
+	long long N = 10LL; 
+	long long K = 10LL; 
+	long long _ = 0LL; 
+END
+CASE(1)
+	long long N = 100LL; 
+	long long K = 1LL; 
+	long long _ = 99LL; 
+END
+CASE(2)
+	long long N = 1000LL; 
+	long long K = 999LL; 
+	long long _ = 1LL; 
+END
+CASE(3)
+	long long N = 10LL; 
+	long long K = 5LL; 
+	long long _ = 3LL; 
+END
+CASE(4)
+	long long N = 1234567898765LL; 
+	long long K = 658167578LL; 
+	long long _ = -1LL;
+END
+/*
+CASE(5)
+	long long N = LL; 
+	long long K = LL; 
+	long long _ = LL; 
+END
+*/
+}
+// END CUT HERE