제출 #532721

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
532721		Alex_tz307	3단 점프 (JOI19_jumps)	C++17	100 / 100	1073 ms	63896 KiB

jumps

#include <bits/stdc++.h>
#define INF 0x3f3f3f3f

using namespace std;

const int kN = 5e5;
int a[1 + kN], s1[1 + kN], s2[1 + kN], dr1[1 + kN], dr2[1 + kN], sol[kN];
vector<pair<int, int>> q[1 + kN];

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

struct ST {
  int n;
  vector<int> maxSum, tmax, best;

  ST(int N) : n(N) {
    int dim = 1;
    while (dim < n) {
      dim *= 2;
    }
    dim *= 2;
    maxSum.resize(dim, -INF);
    tmax.resize(dim);
    best.resize(dim, -INF);
  }

  void build(int x, int lx, int rx) {
    if (lx == rx) {
      tmax[x] = a[lx];
      return;
    }
    int mid = (lx + rx) / 2;
    build(x * 2, lx, mid);
    build(x * 2 + 1, mid + 1, rx);
    tmax[x] = max(tmax[x * 2], tmax[x * 2 + 1]);
  }

  void push(int x, int lx, int rx) {
    if (lx == rx) {
      return;
    }
    for (int i = 0; i < 2; ++i) {
      maxSelf(maxSum[x * 2 + i], maxSum[x]);
      maxSelf(best[x * 2 + i], maxSum[x * 2 + i] + tmax[x * 2 + i]);
    }
    maxSelf(best[x], max(best[x * 2], best[x * 2 + 1]));
  }

  void update(int x, int lx, int rx, int st, int dr, int sum) {
    if (st <= lx && rx <= dr) {
      maxSelf(maxSum[x], sum);
      maxSelf(best[x], maxSum[x] + tmax[x]);
      push(x, lx, rx);
      return;
    }
    push(x, lx, rx);
    int mid = (lx + rx) / 2;
    if (st <= mid) {
      update(x * 2, lx, mid, st, dr, sum);
    }
    if (mid < dr) {
      update(x * 2 + 1, mid + 1, rx, st, dr, sum);
    }
    maxSelf(best[x], max(best[x * 2], best[x * 2 + 1]));
  }

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

  int query(int x, int lx, int rx, int st, int dr) {
    push(x, lx, rx);
    if (st <= lx && rx <= dr) {
      return best[x];
    }
    int mid = (lx + rx) / 2, ans = 0;
    if (st <= mid) {
      maxSelf(ans, query(x * 2, lx, mid, st, dr));
    }
    if (mid < dr) {
      maxSelf(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;
  int vf1 = 0, vf2 = 0;
  for (int i = 1; i <= n; ++i) {
    cin >> a[i];
    while (vf1 && a[s1[vf1]] <= a[i]) {
      dr1[s1[vf1]] = i;
      vf1 -= 1;
    }
    while (vf2 && a[s2[vf2]] < a[i]) {
      dr2[s2[vf2]] = i;
      vf2 -= 1;
    }
    s1[++vf1] = i;
    s2[++vf2] = i;
    dr1[i] = dr2[i] = n + 1;
  }
  ST t(n);
  t.build(1, 1, n);
  int m;
  cin >> m;
  for (int i = 0; i < m; ++i) {
    int l, r;
    cin >> l >> r;
    q[l].emplace_back(r, i);
  }
  for (int i = n - 2; i > 0; --i) {
    int j = i + 1;
    while (j <= n && j <= dr1[i]) {
      t.update(2 * j - i, n, a[i] + a[j]);
      j = dr2[j];
    }
    for (auto it : q[i]) {
      int k, index;
      tie(k, index) = it;
      sol[index] = t.query(i + 2, k);
    }
  }
  for (int i = 0; i < m; ++i) {
    cout << sol[i] << '\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: 5 / 5
• Subtask 2: 14 / 14
• Subtask 3: 27 / 27
• Subtask 4: 54 / 54