Problem p02652 (C++) — buggy submission, verdict: Time Limit Exceeded

//~ while (clock()<=69*CLOCKS_PER_SEC)
//~ #pragma comment(linker, "/stack:200000000")
#ifndef LOCAL
#pragma GCC optimize("O3")
#endif
//~ #pragma GCC optimize("Ofast")
//~ #pragma GCC
//target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native") ~ #pragma
//GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ALL(x) (x).begin(), (x).end()
#define SZ(x) ((int)(x).size())
#define st first
#define nd second

using namespace __gnu_pbds;
using namespace std;

template <typename T>
using ordered_set =
    tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define sim template <class c
#define ris return *this
#define dor > debug &operator<<
#define eni(x)                                                                 \\
  sim > typename enable_if<sizeof dud<c>(0) x 1, debug &>::type operator<<(    \\
            c i) {
sim > struct rge {
  c b, e;
};
sim > rge<c> range(c i, c j) { return rge<c>{i, j}; }
sim > auto dud(c *x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
#ifdef LOCAL
  ~debug() { cerr << endl; }
  eni(!=) cerr << boolalpha << i;
  ris;
} eni(==) ris << range(begin(i), end(i));
}
sim, class b dor(pair<b, c> d) {
  ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d) {
  *this << "[";
  for (auto it = d.b; it != d.e; ++it)
    *this << ", " + 2 * (it == d.b) << *it;
  ris << "]";
}
#else
  sim dor(const c &) { ris; }
#endif
}
;
#define imie(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "

#define shandom_ruffle random_shuffle

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vll = vector<ll>;

struct SegTree {
  struct Node {
    int push;
    int maxval;

    Node() : push(0), maxval(0){};

    Node Merge(const Node &rhs) const {
      Node ans;
      ans.maxval = max(maxval, rhs.maxval);
      return ans;
    }
  };

  vector<Node> nodes;
  int base;

  SegTree(int n) : base(1) {
    while (base < n + 1) {
      base *= 2;
    }
    nodes.resize(base * 2);
    for (int i = base - 1; i >= 0; --i) {
      nodes[i] = nodes[i * 2].Merge(nodes[i * 2 + 1]);
    }
  }

  int lv, rv, valv;

  void Touch(int v) {
    if (v < base) {
      for (int s : {v * 2, v * 2 + 1}) {
        nodes[s].maxval += nodes[v].push;
        nodes[s].push += nodes[v].push;
      }
    }
    nodes[v].push = 0;
  }

  void AddValRec(int lbase, int rbase, int v) {
    if (lbase >= rv || rbase <= lv) {
      return;
    }
    Touch(v);
    if (lv <= lbase && rbase <= rv) {
      nodes[v].maxval += valv;
      nodes[v].push += valv;
      return;
    }

    const int mid = (lbase + rbase) / 2;
    AddValRec(lbase, mid, v * 2);
    AddValRec(mid, rbase, v * 2 + 1);
    nodes[v] = nodes[v * 2].Merge(nodes[v * 2 + 1]);
  }

  void AddVal(int L, int R, int val) {
    lv = L;
    rv = R;
    valv = val;
    return AddValRec(0, base, 1);
  }
};

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout << fixed << setprecision(11);
  cerr << fixed << setprecision(6);

  string s;
  cin >> s;
  int n = SZ(s);

  int mx = 0, cur = 0;
  for (char ch : s) {
    cur += (ch == '1' ? 1 : -1);
    mx = max(mx, cur);
  }
  int ans = 1e9;

  for (int iter = 0; iter <= 1; ++iter) {
    SegTree tree(n + 2);
    for (int i = 0; i < n; ++i) {
      tree.AddVal(i + 1, n + 1, s[i] == '1' ? 1 : -1);
    }

    int cur = 0;
    int mnval = 0;

    for (int i = 0; i < n; ++i) {
      if (s[i] == '?') {
        tree.AddVal(i + 1, n + 1, +2);
        if (tree.nodes[1].maxval > mx) {
          tree.AddVal(i + 1, n + 1, -2);
          cur -= 1;
        } else {
          cur += 1;
        }
      } else {
        cur += (s[i] == '0' ? -1 : 1);
      }
      mnval = min(mnval, cur);
    }

    ans = min(ans, tree.nodes[1].maxval - mnval);
    ++mx;
  }

  cout << ans << "\\n";
}


Error: TLE

Fixed submission:

//~ while (clock()<=69*CLOCKS_PER_SEC)
//~ #pragma comment(linker, "/stack:200000000")
#ifndef LOCAL
#pragma GCC optimize("O3")
#endif
//~ #pragma GCC optimize("Ofast")
//~ #pragma GCC
//target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native") ~ #pragma
//GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ALL(x) (x).begin(), (x).end()
#define SZ(x) ((int)(x).size())
#define st first
#define nd second

using namespace __gnu_pbds;
using namespace std;

template <typename T>
using ordered_set =
    tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define sim template <class c
#define ris return *this
#define dor > debug &operator<<
#define eni(x)                                                                 \\
  sim > typename enable_if<sizeof dud<c>(0) x 1, debug &>::type operator<<(    \\
            c i) {
sim > struct rge {
  c b, e;
};
sim > rge<c> range(c i, c j) { return rge<c>{i, j}; }
sim > auto dud(c *x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
#ifdef LOCAL
  ~debug() { cerr << endl; }
  eni(!=) cerr << boolalpha << i;
  ris;
} eni(==) ris << range(begin(i), end(i));
}
sim, class b dor(pair<b, c> d) {
  ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d) {
  *this << "[";
  for (auto it = d.b; it != d.e; ++it)
    *this << ", " + 2 * (it == d.b) << *it;
  ris << "]";
}
#else
  sim dor(const c &) { ris; }
#endif
}
;
#define imie(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "

#define shandom_ruffle random_shuffle

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vll = vector<ll>;

struct SegTree {
  struct Node {
    int push;
    int minval;
    int maxval;
    int wheremin;

    Node() : push(0), minval(0), maxval(0), wheremin(0){};

    Node Merge(const Node &rhs) const {
      Node ans;
      ans.minval = min(minval, rhs.minval);
      ans.maxval = max(maxval, rhs.maxval);
      ans.wheremin = 1e9;
      if (ans.minval == minval) {
        ans.wheremin = min(ans.wheremin, wheremin);
      } else {
        ans.wheremin = min(ans.wheremin, rhs.wheremin);
      }
      return ans;
    }
  };

  vector<Node> nodes;
  int base;

  SegTree(int n) : base(1) {
    while (base < n + 1) {
      base *= 2;
    }
    nodes.resize(base * 2);
    for (int i = 0; i < base; ++i) {
      nodes[base + i].wheremin = i;
    }
    for (int i = base - 1; i >= 0; --i) {
      nodes[i] = nodes[i * 2].Merge(nodes[i * 2 + 1]);
    }
  }

  int lv, rv, valv;

  void Touch(int v) {
    if (v < base) {
      for (int s : {v * 2, v * 2 + 1}) {
        nodes[s].minval += nodes[v].push;
        nodes[s].maxval += nodes[v].push;
        nodes[s].push += nodes[v].push;
      }
    }
    nodes[v].push = 0;
  }

  void AddValRec(int lbase, int rbase, int v) {
    if (lbase >= rv || rbase <= lv) {
      return;
    }
    Touch(v);
    if (lv <= lbase && rbase <= rv) {
      nodes[v].minval += valv;
      nodes[v].maxval += valv;
      nodes[v].push += valv;
      return;
    }

    const int mid = (lbase + rbase) / 2;
    AddValRec(lbase, mid, v * 2);
    AddValRec(mid, rbase, v * 2 + 1);
    nodes[v] = nodes[v * 2].Merge(nodes[v * 2 + 1]);
  }

  void AddVal(int L, int R, int val) {
    lv = L;
    rv = R;
    valv = val;
    return AddValRec(0, base, 1);
  }
};

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout << fixed << setprecision(11);
  cerr << fixed << setprecision(6);

  string s;
  cin >> s;
  int n = SZ(s);

  int mx = 0, cur = 0;
  for (char ch : s) {
    cur += (ch == '1' ? 1 : -1);
    mx = max(mx, cur);
  }
  int ans = 1e9;

  for (int iter = 0; iter <= 1; ++iter) {
    SegTree tree(n + 2);
    for (int i = 0; i < n; ++i) {
      tree.AddVal(i + 1, n + 1, s[i] == '1' ? 1 : -1);
    }

    for (int i = 0; i < n; ++i) {
      if (s[i] == '?') {
        tree.AddVal(i + 1, n + 1, +2);
        if (tree.nodes[1].maxval > mx) {
          tree.AddVal(i + 1, n + 1, -2);
        }
      }
    }

    ans = min(ans, tree.nodes[1].maxval - tree.nodes[1].minval);
    ++mx;
  }

  cout << ans << "\\n";
}