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답안 #199387

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
199387 2020-02-01T03:04:18 Z EntityIT 3단 점프 (JOI19_jumps) C++14
100 / 100
 1221 ms 99196 KB 
/*
  Just consider the pair(a, b) such that with every a < k < b, a[a] > a[k] and a[b] > a[k]
  The number of these pairs is just O(n): the proof can be expressed by the code finding these pairs
  The rest is quite easy
*/
#include<bits/stdc++.h>

using namespace std;

#define all(x) (x).begin(), (x).end()
#define sz(x) ( (int)(x).size() )
using LL = long long;

const int inf = 1e9;
mt19937 rng( (uint32_t)chrono::steady_clock::now().time_since_epoch().count() );

template<class T>
inline bool asMn(T &a, const T &b) { return a > b ? a = b, true : false; }
template<class T>
inline bool asMx(T &a, const T &b) { return a < b ? a = b, true : false; }

int n;
vector<int> a;

struct Node {
  int mxA, mxOth, mx;
  Node(int _mxA = 0, int _mxOth = 0, int _mx = 0) : mxA(_mxA), mxOth(_mxOth), mx(_mx) {}
};

struct It {
  vector<Node> node;
  It(int nNode) { node.assign(nNode, 0); }

  void build(int i = 1, int Left = 0, int Right = n - 1) {
    if (Left == Right) {
      node[i] = Node(a[Left], -inf, -inf);
      return ;
    }
    int Mid = (Left + Right) >> 1;
    build(i << 1, Left, Mid);
    build(i << 1 | 1, Mid + 1, Right);
    node[i].mxA = max(node[i << 1].mxA, node[i << 1 | 1].mxA);
  }

  void upd(int l, int r, int val, int i = 1, int Left = 0, int Right = n - 1) {
    if (i != 1) {
      asMx(node[i].mxOth, node[i >> 1].mxOth);
      asMx(node[i].mx, node[i].mxOth + node[i].mxA);
    }

    if (Right < l || r < Left) return ;
    if (l <= Left && Right <= r) {
      asMx(node[i].mxOth, val); asMx(node[i].mx, node[i].mxOth + node[i].mxA);
      return ;
    }

    int Mid = (Left + Right) >> 1;
    upd(l, r, val, i << 1, Left, Mid);
    upd(l, r, val, i << 1 | 1, Mid + 1, Right);
    node[i].mx = max(node[i << 1].mx, node[i << 1 | 1].mx);
  }

  int getMx(int l, int r, int i = 1, int Left = 0, int Right = n - 1) {
    if (i != 1) {
      asMx(node[i].mxOth, node[i >> 1].mxOth);
      asMx(node[i].mx, node[i].mxOth + node[i].mxA);
    }

    if (Right < l || r < Left) return -inf;
    if (l <= Left && Right <= r) return node[i].mx;

    int Mid = (Left + Right) >> 1;
    return max(getMx(l, r, i << 1, Left, Mid), getMx(l, r, i << 1 | 1, Mid + 1, Right) );
  }
};

int main() {
  ios_base::sync_with_stdio(0); cin.tie(0);

  #ifdef FourLeafClover
  freopen("input", "r", stdin);
  #endif // FourLeafCLover

  cin >> n;
  a.assign(n, 0);
  for (int i = 0; i < n; ++i) cin >> a[i];

  vector<vector<int> > paired(n);
  stack<int> st;
  for (int i = 0; i < n; ++i) {
    while (sz(st) && a[st.top()] <= a[i]) {
      paired[st.top()].emplace_back(i);
      st.pop();
    }
    if (sz(st) ) paired[st.top()].emplace_back(i);

    st.emplace(i);
  }

  int q; cin >> q;
  vector<vector<pair<int, int> > > que(n);
  for (int i = 0; i < q; ++i) {
    int l, r; cin >> l >> r; --l; --r;
    que[l].emplace_back(r, i);
  }

  vector<int> ans(q);
  It it( (n + 5) << 2);
  it.build();
  for (int i = n - 1; i >= 0; --i) {
    for (int j : paired[i]) if ( (j << 1) - i <= n - 1) it.upd( (j << 1) - i, n - 1, a[i] + a[j]);

    for (auto query : que[i]) ans[query.second] = it.getMx(i, query.first);
  }

  for (int i = 0; i < q; ++i) cout << ans[i] << '\n';

  return 0;
}

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 376 KB Output is correct
2 Correct 6 ms 380 KB Output is correct
3 Correct 5 ms 376 KB Output is correct
4 Correct 5 ms 376 KB Output is correct
5 Correct 5 ms 376 KB Output is correct
6 Correct 5 ms 376 KB Output is correct
7 Correct 5 ms 376 KB Output is correct
8 Correct 5 ms 376 KB Output is correct
9 Correct 5 ms 376 KB Output is correct
10 Correct 6 ms 376 KB Output is correct

Subtask #2
14.0 / 14.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 376 KB Output is correct
2 Correct 6 ms 380 KB Output is correct
3 Correct 5 ms 376 KB Output is correct
4 Correct 5 ms 376 KB Output is correct
5 Correct 5 ms 376 KB Output is correct
6 Correct 5 ms 376 KB Output is correct
7 Correct 5 ms 376 KB Output is correct
8 Correct 5 ms 376 KB Output is correct
9 Correct 5 ms 376 KB Output is correct
10 Correct 6 ms 376 KB Output is correct
11 Correct 312 ms 14328 KB Output is correct
12 Correct 316 ms 14328 KB Output is correct
13 Correct 321 ms 14328 KB Output is correct
14 Correct 313 ms 14396 KB Output is correct
15 Correct 314 ms 14328 KB Output is correct
16 Correct 316 ms 13688 KB Output is correct
17 Correct 306 ms 13816 KB Output is correct
18 Correct 322 ms 13688 KB Output is correct
19 Correct 320 ms 14304 KB Output is correct

Subtask #3
27.0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Correct 176 ms 28064 KB Output is correct
2 Correct 105 ms 27896 KB Output is correct
3 Correct 103 ms 28792 KB Output is correct
4 Correct 181 ms 28180 KB Output is correct
5 Correct 183 ms 28152 KB Output is correct
6 Correct 175 ms 27512 KB Output is correct
7 Correct 170 ms 27384 KB Output is correct
8 Correct 178 ms 27384 KB Output is correct
9 Correct 196 ms 28020 KB Output is correct

Subtask #4
54.0 / 54.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 376 KB Output is correct
2 Correct 6 ms 380 KB Output is correct
3 Correct 5 ms 376 KB Output is correct
4 Correct 5 ms 376 KB Output is correct
5 Correct 5 ms 376 KB Output is correct
6 Correct 5 ms 376 KB Output is correct
7 Correct 5 ms 376 KB Output is correct
8 Correct 5 ms 376 KB Output is correct
9 Correct 5 ms 376 KB Output is correct
10 Correct 6 ms 376 KB Output is correct
11 Correct 312 ms 14328 KB Output is correct
12 Correct 316 ms 14328 KB Output is correct
13 Correct 321 ms 14328 KB Output is correct
14 Correct 313 ms 14396 KB Output is correct
15 Correct 314 ms 14328 KB Output is correct
16 Correct 316 ms 13688 KB Output is correct
17 Correct 306 ms 13816 KB Output is correct
18 Correct 322 ms 13688 KB Output is correct
19 Correct 320 ms 14304 KB Output is correct
20 Correct 176 ms 28064 KB Output is correct
21 Correct 105 ms 27896 KB Output is correct
22 Correct 103 ms 28792 KB Output is correct
23 Correct 181 ms 28180 KB Output is correct
24 Correct 183 ms 28152 KB Output is correct
25 Correct 175 ms 27512 KB Output is correct
26 Correct 170 ms 27384 KB Output is correct
27 Correct 178 ms 27384 KB Output is correct
28 Correct 196 ms 28020 KB Output is correct
29 Correct 1188 ms 93432 KB Output is correct
30 Correct 977 ms 92792 KB Output is correct
31 Correct 1056 ms 94840 KB Output is correct
32 Correct 1196 ms 93432 KB Output is correct
33 Correct 1221 ms 93432 KB Output is correct
34 Correct 1149 ms 91128 KB Output is correct
35 Correct 1180 ms 90888 KB Output is correct
36 Correct 1094 ms 90872 KB Output is correct
37 Correct 1148 ms 92280 KB Output is correct
38 Correct 863 ms 99196 KB Output is correct
39 Correct 823 ms 99068 KB Output is correct
40 Correct 813 ms 95736 KB Output is correct
41 Correct 812 ms 95352 KB Output is correct
42 Correct 826 ms 95352 KB Output is correct
43 Correct 824 ms 97056 KB Output is correct
44 Correct 840 ms 98552 KB Output is correct
45 Correct 877 ms 98424 KB Output is correct
46 Correct 843 ms 95352 KB Output is correct
47 Correct 851 ms 95124 KB Output is correct
48 Correct 857 ms 94904 KB Output is correct
49 Correct 821 ms 97016 KB Output is correct
50 Correct 938 ms 96700 KB Output is correct
51 Correct 966 ms 96680 KB Output is correct
52 Correct 983 ms 94200 KB Output is correct
53 Correct 962 ms 93692 KB Output is correct
54 Correct 950 ms 93816 KB Output is correct
55 Correct 1002 ms 95456 KB Output is correct