Problem p03580 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <algorithm>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <vector>
#define _USE_MATH_DEFINES
#include <cassert>
#include <cfloat>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
using namespace std;

#define EPS 1e-12
#define ull unsigned long long
#define ll long long
#define VI vector<ll>
#define PII pair<ll, ll>
#define VVI vector<vector<ll>>
#define REP(i, n) for (int i = 0, _n = (n); (i) < (int)_n; ++i)
#define RANGE(i, a, b) for (int i = (int)a, _b = (int)(b); (i) < _b; ++i)
#define FOR(i, c)                                                              \
  for (__typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define ALL(c) (c).begin(), (c).end()
#define ALLR(c) (c).rbegin(), (c).rend()
#define PB push_back
#define MP(a, b) make_pair(a, b)
#define POPCOUNT __builtin_popcount
#define POPCOUNTLL __builtin_popcountll
#define CLEAR(table, v) memset(table, v, sizeof(table));
#define PRINT1(table, D0)                                                      \
  REP(d0, D0) cout << table[d0] << " ";                                        \
  cout << "\n";
#define PRINT2(table, D0, D1)                                                  \
  REP(d0, D0) {                                                                \
    REP(d1, D1) cout << table[d0][d1] << " ";                                  \
    cout << "\n";                                                              \
  }
#define PRINT3(table, D0, D1, D2)                                              \
  REP(d0, D0) {                                                                \
    REP(d1, D1) {                                                              \
      REP(d2, D2) cout << table[d0][d1][d2] << " ";                            \
      cout << "\n";                                                            \
    }                                                                          \
    cout << "\n";                                                              \
  }
#define UNIFORM_DOUBLE(a, b)                                                   \
  (((b - a) * (double)rand() / RAND_MAX) + a)      // [a, b)
#define UNIFORM_LL(a, b) (ll) UNIFORM_DOUBLE(a, b) // [a, b)
#define IN(v, lo, hi) ((lo) <= (v) && (v) < (hi))
#define DD(v) cout << #v << ": " << v << endl
template <typename T0, typename T1>
std::ostream &operator<<(std::ostream &os, const pair<T0, T1> &v) {
  os << v.first << ": " << v.second << " ";
  return os;
}
template <typename T>
std::ostream &operator<<(std::ostream &os, const vector<T> &v) {
  for (int i = 0; i < (int)v.size(); i++) {
    os << v[i] << " ";
  }
  return os;
}
template <typename T>
std::ostream &operator<<(std::ostream &os, const vector<vector<T>> &v) {
  for (int i = 0; i < (int)v.size(); i++) {
    os << v[i] << endl;
  }
  return os;
}
template <typename T>
std::ostream &operator<<(std::ostream &os, const set<T> &v) {
  vector<T> tmp(v.begin(), v.end());
  os << tmp;
  return os;
}
template <typename T>
std::ostream &operator<<(std::ostream &os, const deque<T> &v) {
  vector<T> tmp(v.begin(), v.end());
  os << tmp;
  return os;
}
template <typename T0, typename T1>
std::ostream &operator<<(std::ostream &os, const map<T0, T1> &v) {
  for (typename map<T0, T1>::const_iterator p = v.begin(); p != v.end(); p++) {
    os << p->first << ": " << p->second << " ";
  }
  return os;
}

#define MOD 1000000007LL
#define INF (1LL << 60)

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  ll N;
  string s;
  while (cin >> N >> s) {
    //		DD(s);
    VI dp(N);
    VI sr(N), sl(N);
    {
      ll c = 0;
      REP(i, N) {
        if (s[i] == '0')
          c = 0;
        if (s[i] == '1')
          c++;
        sl[i] = c;
      }
    }
    {
      ll c = 0;
      REP(ii, N) {
        ll i = N - 1 - ii;
        if (s[i] == '0')
          c = 0;
        if (s[i] == '1')
          c++;
        sr[i] = c;
      }
    }
    map<ll, vector<pair<ll, pair<ll, ll>>>> h;
    RANGE(i, 1, N - 1) if (s[i] == '0' && s[i - 1] == '1' && s[i + 1] == '1') {
      VI ss, es;
      RANGE(j, i - 1 - sl[i - 1] + 1, i - 1 + 1) ss.PB(j);
      RANGE(j, i + 1, i + 1 + sr[i + 1] - 1 + 1) es.PB(j);
      for (auto s : ss)
        for (auto e : es) {
          ll cost = max((i - 1) - s + 1, e - (i + 1) + 1);
          h[e].PB(MP(s, MP(e, cost)));
          //				cout<<"good "<<s<<" "<<e<<"
          //"<<cost<<endl;
        }
    }
    //		DD(h);
    REP(i, N) {
      dp[i] = i - 1 >= 0 ? dp[i - 1] : 0;
      if (!h.count(i))
        continue;

      auto &rs = h[i];
      for (auto &v : rs) {
        // k ... j ... i
        // 1 1 1 0 1 1 1
        ll s = v.first;
        ll e = v.second.first;
        ll cost = v.second.second;
        dp[i] = max(dp[i], (s - 1 >= 0 ? dp[s - 1] : 0) + cost);
      }
    }
    //		REP(i, N) {
    //			dp[i] = i-1>=0 ? dp[i-1] : 0;
    //			if(s[i]=='1') {
    //				for(int j=i-1;j>=0;j--) {
    //					if(s[j]=='0') {
    //						for(int k=j-1;k>=0;k--) {
    //							if(s[k]!='1') break;
    //							// k ... j ... i
    //							// 1 1 1 0 1 1 1
    //							dp[i] = max(dp[i], (k-1>=0 ? dp[k-1] : 0) + max(j-k,
    //i-j));
    //						}
    //						break;
    //					}
    //				}
    //			}
    //		}
    //		DD(dp);
    cout << dp[N - 1] << endl;
    //		break;
  }

  return 0;
}


Fixed submission:
#include <algorithm>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <vector>
#define _USE_MATH_DEFINES
#include <cassert>
#include <cfloat>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
using namespace std;

#define EPS 1e-12
#define ull unsigned long long
#define ll long long
#define VI vector<ll>
#define PII pair<ll, ll>
#define VVI vector<vector<ll>>
#define REP(i, n) for (int i = 0, _n = (n); (i) < (int)_n; ++i)
#define RANGE(i, a, b) for (int i = (int)a, _b = (int)(b); (i) < _b; ++i)
#define FOR(i, c)                                                              \
  for (__typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define ALL(c) (c).begin(), (c).end()
#define ALLR(c) (c).rbegin(), (c).rend()
#define PB push_back
#define MP(a, b) make_pair(a, b)
#define POPCOUNT __builtin_popcount
#define POPCOUNTLL __builtin_popcountll
#define CLEAR(table, v) memset(table, v, sizeof(table));
#define PRINT1(table, D0)                                                      \
  REP(d0, D0) cout << table[d0] << " ";                                        \
  cout << "\n";
#define PRINT2(table, D0, D1)                                                  \
  REP(d0, D0) {                                                                \
    REP(d1, D1) cout << table[d0][d1] << " ";                                  \
    cout << "\n";                                                              \
  }
#define PRINT3(table, D0, D1, D2)                                              \
  REP(d0, D0) {                                                                \
    REP(d1, D1) {                                                              \
      REP(d2, D2) cout << table[d0][d1][d2] << " ";                            \
      cout << "\n";                                                            \
    }                                                                          \
    cout << "\n";                                                              \
  }
#define UNIFORM_DOUBLE(a, b)                                                   \
  (((b - a) * (double)rand() / RAND_MAX) + a)      // [a, b)
#define UNIFORM_LL(a, b) (ll) UNIFORM_DOUBLE(a, b) // [a, b)
#define IN(v, lo, hi) ((lo) <= (v) && (v) < (hi))
#define DD(v) cout << #v << ": " << v << endl
template <typename T0, typename T1>
std::ostream &operator<<(std::ostream &os, const pair<T0, T1> &v) {
  os << v.first << ": " << v.second << " ";
  return os;
}
template <typename T>
std::ostream &operator<<(std::ostream &os, const vector<T> &v) {
  for (int i = 0; i < (int)v.size(); i++) {
    os << v[i] << " ";
  }
  return os;
}
template <typename T>
std::ostream &operator<<(std::ostream &os, const vector<vector<T>> &v) {
  for (int i = 0; i < (int)v.size(); i++) {
    os << v[i] << endl;
  }
  return os;
}
template <typename T>
std::ostream &operator<<(std::ostream &os, const set<T> &v) {
  vector<T> tmp(v.begin(), v.end());
  os << tmp;
  return os;
}
template <typename T>
std::ostream &operator<<(std::ostream &os, const deque<T> &v) {
  vector<T> tmp(v.begin(), v.end());
  os << tmp;
  return os;
}
template <typename T0, typename T1>
std::ostream &operator<<(std::ostream &os, const map<T0, T1> &v) {
  for (typename map<T0, T1>::const_iterator p = v.begin(); p != v.end(); p++) {
    os << p->first << ": " << p->second << " ";
  }
  return os;
}

#define MOD 1000000007LL
#define INF (1LL << 60)

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  ll N;
  string s;
  while (cin >> N >> s) {
    //		DD(s);
    VI dp(N);
    VI sr(N), sl(N);
    {
      ll c = 0;
      REP(i, N) {
        if (s[i] == '0')
          c = 0;
        if (s[i] == '1')
          c++;
        sl[i] = c;
      }
    }
    {
      ll c = 0;
      REP(ii, N) {
        ll i = N - 1 - ii;
        if (s[i] == '0')
          c = 0;
        if (s[i] == '1')
          c++;
        sr[i] = c;
      }
    }
    map<ll, vector<pair<ll, pair<ll, ll>>>> h;
    RANGE(i, 1, N - 1) if (s[i] == '0' && s[i - 1] == '1' && s[i + 1] == '1') {
      VI ss, es;
      RANGE(s, i - 1 - sl[i - 1] + 1, i - 1 + 1) {
        ll cost = max(1, i - 1 - s + 1);
        ll e = i + 1;
        h[e].PB(MP(s, MP(e, cost)));
      }
      RANGE(e, i + 1, i + 1 + sr[i + 1] - 1 + 1) {
        ll cost = max(1, e - (i + 1) + 1);
        ll s = i - 1;
        h[e].PB(MP(s, MP(e, cost)));
      }
    }
    //		DD(h);
    REP(i, N) {
      dp[i] = i - 1 >= 0 ? dp[i - 1] : 0;
      if (!h.count(i))
        continue;

      auto &rs = h[i];
      for (auto &v : rs) {
        // k ... j ... i
        // 1 1 1 0 1 1 1
        ll s = v.first;
        ll e = v.second.first;
        ll cost = v.second.second;
        dp[i] = max(dp[i], (s - 1 >= 0 ? dp[s - 1] : 0) + cost);
      }
    }
    //		REP(i, N) {
    //			dp[i] = i-1>=0 ? dp[i-1] : 0;
    //			if(s[i]=='1') {
    //				for(int j=i-1;j>=0;j--) {
    //					if(s[j]=='0') {
    //						for(int k=j-1;k>=0;k--) {
    //							if(s[k]!='1') break;
    //							// k ... j ... i
    //							// 1 1 1 0 1 1 1
    //							dp[i] = max(dp[i], (k-1>=0 ? dp[k-1] : 0) + max(j-k,
    //i-j));
    //						}
    //						break;
    //					}
    //				}
    //			}
    //		}
    //		DD(dp);
    cout << dp[N - 1] << endl;
    //		break;
  }

  return 0;
}