Submission #529712

#	Time	Username	Problem	Language	Result	Execution time	Memory
529712		Alex_tz307	Divide and conquer (IZhO14_divide)	C++17	100 / 100	90 ms	5996 KiB

divide

#include <bits/stdc++.h>

using namespace std;

const int kN = 1e5;
int x[1 + kN], e[1 + kN];
int64_t sum[1 + kN];

void maxSelf(int64_t &x, int64_t y) {
  if (x < y) {
    x = y;
  }
}

struct ST {
  int n;
  vector<int64_t> t, lazy;

  ST(int N) : n(N) {
    int dim = 1;
    while (dim < n) {
      dim *= 2;
    }
    dim *= 2;
    t.resize(dim);
    lazy.resize(dim);
  }

  void updateNode(int x, int64_t v) {
    t[x] += v;
    lazy[x] += v;
  }

  void push(int x) {
    if (lazy[x] == 0) {
      return;
    }
    for (int i = 0; i < 2; ++i) {
      updateNode(x * 2 + i, lazy[x]);
    }
    lazy[x] = 0;
  }

  void update(int x, int lx, int rx, int st, int dr, int v) {
    if (st <= lx && rx <= dr) {
      updateNode(x, v);
      return;
    }
    push(x);
    int mid = (lx + rx) / 2;
    if (st <= mid) {
      update(x * 2, lx, mid, st, dr, v);
    }
    if (mid < dr) {
      update(x * 2 + 1, mid + 1, rx, st, dr, v);
    }
    t[x] = max(t[x * 2], t[x * 2 + 1]);
  }

  void update(int st, int dr, int64_t v) {
    if (dr < st) {
      return;
    }
    update(1, 1, n, st, dr, v);
  }

  int query(int x, int lx, int rx, int st, int dr) {
    if (lx == rx) {
      if (t[x] < 0) {
        return 0;
      }
      return lx;
    }
    push(x);
    int mid = (lx + rx) / 2, ans = 0;
    if (st <= mid && t[x * 2] >= 0) {
      ans = query(x * 2, lx, mid, st, dr);
    }
    if (ans == 0 && mid < dr && t[x * 2 + 1] >= 0) {
      ans = query(x * 2 + 1, mid + 1, rx, st, dr);
    }
    return ans;
  }

  int query(int st, int dr) {
    return query(1, 1, n, st, dr);
  }
};

void testCase() {
  int n;
  cin >> n;
  for (int i = 1; i <= n; ++i) {
    int g;
    cin >> x[i] >> g >> e[i];
    sum[i] = sum[i - 1] + g;
  }
  ST t(n);
  int64_t ans = 0;
  for (int r = 1; r <= n; ++r) {
    t.update(1, r - 1, e[r] - (x[r] - x[r - 1]));
    t.update(r, r, e[r]);
    int l = t.query(1, r);
    maxSelf(ans, sum[r] - sum[l - 1]);
  }
  cout << ans << '\n';
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  int tests = 1;
  for (int tc = 0; tc < tests; ++tc) {
    testCase();
  }
  return 0;
}

• Subtask 1: 17 / 17
• Subtask 2: 31 / 31
• Subtask 3: 52 / 52