Submission #815680

#	Time	Username	Problem	Language	Result	Execution time	Memory
815680		MilosMilutinovic	Fish 2 (JOI22_fish2)	C++14	8 / 100	4054 ms	29688 KiB

fish2

/**
 *    author:  wxhtzdy
 *    created: 07.08.2023 10:57:57
**/
#include <bits/stdc++.h>

using namespace std;

namespace mncnt {
  struct node {
    int mn;
    int cnt;
  };
  node comb(node l, node r) {
    node res;
    res.mn = min(l.mn, r.mn);
    res.cnt = (l.mn == res.mn ? l.cnt : 0) + (r.mn == res.mn ? r.cnt : 0);
    return res;
  }
  vector<node> st;
  vector<int> lzy;
  int n;
  void init(int _n) {
    n = _n;
    st.resize(8 * n);
    lzy.resize(8 * n);
  }
  void push(int x) {
    st[2 * x].mn += lzy[x];
    st[2 * x + 1].mn += lzy[x];
    lzy[2 * x] += lzy[x];
    lzy[2 * x + 1] += lzy[x];
    lzy[x] = 0;
  }
  void pull(int x) {
    st[x] = comb(st[2 * x], st[2 * x + 1]);
  }
  void build(int x, int l, int r) {
    lzy[x] = 0;
    if (l == r) {
      st[x].mn = 0;
      st[x].cnt = 1;
      return;
    }
    int mid = l + r >> 1;
    build(x * 2, l, mid);
    build(x * 2 + 1, mid + 1, r);
    pull(x);
  }
  void update(int x, int l, int r, int ll, int rr, int v) {
    if (l > r || l > rr || r < ll || ll > rr) {
      return;
    }
    if (ll <= l && r <= rr) {
      lzy[x] += v;
      st[x].mn += v;
      push(x);
      return;      
    }
    push(x);
    int mid = l + r >> 1;
    update(x * 2, l, mid, ll, rr, v);
    update(x * 2 + 1, mid + 1, r, ll, rr, v);
    pull(x);
  }
  node query(int x, int l, int r, int ll, int rr) {
    if (l > r || l > rr || r < ll || ll > rr) {
      return {(int) 1e9, 0};
    }
    if (ll <= l && r <= rr) {
      return st[x];
    }
    push(x);
    int mid = l + r >> 1;
    node ndl = query(2 * x, l, mid, ll, rr);
    node ndr = query(2 * x + 1, mid + 1, r, ll, rr);
    pull(x);
    return comb(ndl, ndr);
  }
  void update(int l, int r, int v) {
    update(1, 0, n - 1, l, r, v);
  }
  int get(int l, int r) {
    if (l > r) {
      return 0;
    }
    node nd = query(1, 0, n - 1, l, r);
    assert(nd.mn >= 0);
    return nd.mn == 0 ? nd.cnt : 0;
  }
};

template <typename T>
class fenwick {
  public:
  vector<T> fenw;
  int n;
  fenwick(int _n) : n(_n) {
    fenw.resize(n);
  }
  void modify(int x, T v) {
    while (x < n) {
      fenw[x] += v;
      x |= (x + 1);
    }
  }
  T get(int x) {
    T v{};
    while (x >= 0) {
      v += fenw[x];
      x = (x & (x + 1)) - 1;
    }
    return v;
  }
};

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);  
  int n;
  cin >> n;
  vector<int> a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  fenwick<long long> fenw(n);
  for (int i = 0; i < n; i++) {
    fenw.modify(i, a[i]);
  }
  auto GetSum = [&](int L, int R) {
    return fenw.get(R) - fenw.get(L - 1);
  };
  const long long inf = (long long) 1e18;
  auto Valid = [&](int L, int R) {
    if (L + 1 >= R) {
      return false;
    }                                                   
    return min((L < 0 ? inf : a[L] * 1LL), (R >= n ? inf : a[R] * 1LL)) > GetSum(L + 1, R - 1);
  };
  vector<vector<pair<int, int>>> segs(8 * n);
  function<void(int, int, int, int, int, int, int)> Add = [&](int x, int l, int r, int ll, int rr, int vl, int vr) {
    if (l > r || l > rr || r < ll || ll > rr) {
      return;
    }
    if (ll <= l && r <= rr) {
      segs[x].emplace_back(vl, vr);
      return;
    }
    int mid = l + r >> 1;
    Add(x * 2, l, mid, ll, rr, vl, vr);
    Add(x * 2 + 1, mid + 1, r, ll, rr, vl, vr);
  };               
  mncnt::init(n);
  auto Build = [&]() {
    mncnt::build(1, 0, n - 1);
    vector<int> stk;
    for (int i = 0; i < n; i++) {
      while (!stk.empty() && a[stk.back()] <= a[i]) {
        if (Valid(stk.back(), i)) {
          // cout << "Bad seg " << stk.back() + 1 << " " << i - 1 << '\n';
          //Add(1, 0, n - 1, max(0, stk.back()), i, stk.back() + 1, i - 1);
          mncnt::update(stk.back() + 1, i - 1, 1);
        }
        stk.pop_back();
      }
      if (stk.empty()) {
        if (Valid(-1, i)) {
          // cout << "Bad seg " << 0 << " " << i - 1 << '\n';
          //Add(1, 0, n - 1, 0, i, 0, i - 1);
          mncnt::update(0, i - 1, 1);
        }
      }
      stk.push_back(i);
    }
    stk.clear();
    for (int i = n - 1; i >= 0; i--) {
      while (!stk.empty() && a[stk.back()] <= a[i]) {
        if (Valid(i, stk.back())) {
          // cout << "Bad seg " << i + 1 << " " << stk.back() - 1 << '\n';
          //Add(1, 0, n - 1, i, min(n - 1, stk.back()), i + 1, stk.back() - 1);  
          mncnt::update(i + 1, stk.back() - 1, 1);
        }
        stk.pop_back();
      }
      if (stk.empty()) {
        if (Valid(i, n)) {
          // cout << "Bad seg " << i + 1 << " " << stk.back() - 1 << '\n';
          //Add(1, 0, n - 1, i, n - 1, i + 1, n - 1);
          mncnt::update(i + 1, n - 1, 1);
        }
      }
      stk.push_back(i);
    }
  };
  int q;
  cin >> q;
  while (q--) {
    int op;
    cin >> op;
    if (op == 1) {
      int x, y;
      cin >> x >> y;
      --x;
      fenw.modify(x, y - a[x]);
      a[x] = y;    
    } else {
      Build();
      int l, r;
      cin >> l >> r;
      --l; --r;
      int L = l, R = r;
      {
        for (int i = L + 1; i <= R; i++) {
          if (GetSum(L, i - 1) < a[i]) {
            l = i;
          }
        }
      }
      {
        for (int i = R - 1; i >= L; i--) {
          if (GetSum(i + 1, R) < a[i]) {
            r = i;
          }
        }
      }
      assert(l <= r);
      //cout << l << " " << r << '\n';
      cout << mncnt::get(l, r) << '\n';
    }
  }
  return 0;
}

Compilation message (stderr)

fish2.cpp: In function 'void mncnt::build(int, int, int)':
fish2.cpp:45:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   45 |     int mid = l + r >> 1;
      |               ~~^~~
fish2.cpp: In function 'void mncnt::update(int, int, int, int, int, int)':
fish2.cpp:61:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   61 |     int mid = l + r >> 1;
      |               ~~^~~
fish2.cpp: In function 'mncnt::node mncnt::query(int, int, int, int, int)':
fish2.cpp:74:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   74 |     int mid = l + r >> 1;
      |               ~~^~~
fish2.cpp: In lambda function:
fish2.cpp:149:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  149 |     int mid = l + r >> 1;
      |               ~~^~~

• Subtask 1: 0 / 5
• Subtask 2: 8 / 8
• Subtask 3: 0 / 12
• Subtask 4: 0 / 23
• Subtask 5: 0 / 35
• Subtask 6: 0 / 17