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ID题目提交者结果用时内存语言文件大小提交时间测评时间
#222578#7567. Joining CatsLainTL 0ms3884kbC++204.0kb2023-10-21 17:39:522023-10-21 17:39:54

Judging History

你现在查看的是最新测评结果

  • [2023-10-21 17:39:54]
  • 评测
  • 测评结果:TL
  • 用时:0ms
  • 内存:3884kb
  • [2023-10-21 17:39:52]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;

#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;

struct Tree {
  typedef int T;
  static constexpr T unit = INT_MAX;
  T f (T a, T b) { return min(a, b); }
  vector<T> s; int n;
  Tree(int n = 0, T def = unit) : s(2*n, def), n(n) {}
  void update(int pos, T val) {
    for (s[pos += n] = val; pos /= 2;)
      s[pos] = f(s[pos * 2], s[pos * 2 + 1]);
  }
  T query(int b, int e) { // query [b, e)
    T ra = unit, rb = unit;
    for (b += n, e += n; b < e; b /= 2, e /= 2) {
      if (b % 2) ra = f(ra, s[b++]);
      if (e % 2) rb = f(s[--e], rb);
    }
    return f(ra, rb);
  }
};

int main() {
  cin.tie(0)->sync_with_stdio(0);
  cin.exceptions(cin.failbit);

  enum {
    LEFT_CUT,
    RIGHT_CUT,
  };

  struct node {
    int l, r, st;
  };

  int n, k;
  cin >> n >> k;
  vi a(n), s(k);
  for (auto& x : a) cin >> x;
  for (auto& x : s) cin >> x;
  reverse(all(s));
  auto compress=  s;
  sort(all(compress));
  compress.erase(unique(all(compress)), compress.end());
  auto get = [&](int x)->int {
    return lower_bound(all(compress), x) - compress.begin();
  };

  // For the value a[i], if I have used j times, what is the next usable?
  vector<vi> next(n, vi(k+1, -1));
  rep(i, 0, n) {
    Tree T(sz(compress));
    for (int j = k; j >= 0; j--) {
      int _ = 1;
      while(_--) {
        int idx = get(a[i]);
        if (idx == sz(compress)) continue;
        int best = T.query(idx, sz(compress));
        if (best == T.unit) continue;
        next[i][j] = best;
      }
      if (j)
        T.update(get(s[j-1]), j-1);
    }
  }

  vector<ll> pref(n), suff(n);
  for (int i = 0; i < n; i++) {
    if (i) pref[i] += pref[i-1];
    pref[i] += a[i];
  }
  for (int i = n-1; i >= 0; i--) {
    if (i != n-1) suff[i] += suff[i+1];
    suff[i] += a[i];
  }
  reverse(all(suff));

  // TODO:
  // 1. Insert the segment at 0 in the correct spot.
  // 2. Iterate in increasing order, and do a BFS. 
  // 3. If you encounter a [x, x] segment, we win
  bool found = false;
  vector<vector<node>> events(k);
  if (next[0][0] != -1)
    events[next[0][0]].push_back({0, n-1, LEFT_CUT});
  if (next[n-1][0] != -1)
    events[next[n-1][0]].push_back({0, n-1, RIGHT_CUT});
  set<pair<int,int>> used;
  rep(i, 0, k) {
    if (found) break;
    if (events[i].empty()) continue;
    for (auto& [l, r, st] : events[i]) {
      if (st == LEFT_CUT) {
        ll want = (l?pref[l-1]:0) + s[i];
        auto it = upper_bound(pref.begin() + l, pref.begin() + r + 1, want);
        if (it == pref.begin()) continue;
        int nl = it - pref.begin(), nr = r;
        if (nl >= nr) {
          found = true;
          break;
        }
        if (used.count({nl, nr})) continue;
        used.insert({nl, nr});

        if (next[nl][i+1] != -1) {
          events[next[nl][i+1]].push_back({nl, nr, LEFT_CUT});
        }
        if (next[nr][i+1] != -1) {
          events[next[nr][i+1]].push_back({nl, nr, RIGHT_CUT});
        }
      } else if (st == RIGHT_CUT) {
        int suffl = (n-1) - r, suffr = (n-1) - l;;
        ll want = (suffl?suff[suffl - 1]: 0) + s[i];
        auto it = upper_bound(suff.begin() + suffl, suff.begin() + suffr + 1, want);
        if (it == suff.begin()) continue;
        int nsuffl =  it - suff.begin(), nsuffr = suffr;
        int nl = n-1-nsuffr, nr = n-1-nsuffl;

        if (nl >= nr) {
          found = true;
          break;
        }
        if (used.count({nl, nr})) continue;
        used.insert({nl, nr});

        if (next[nl][i+1] != -1) {
          events[next[nl][i+1]].push_back({nl, nr, LEFT_CUT});
        }
        if (next[nr][i+1] != -1) {
          events[next[nr][i+1]].push_back({nl, nr, RIGHT_CUT});
        }
      } else assert(false);
    }
  }
  cout << (found?"Yes":"No") << '\n';
}

详细

Test #1:

score: 100
Accepted
time: 0ms
memory: 3544kb

input:

5 2
1 1 1 1 1
2 2

output:

Yes

result:

ok answer is YES

Test #2:

score: 0
Accepted
time: 0ms
memory: 3652kb

input:

6 7
3 2 1 1 2 3
2 2 2 2 2 2 2

output:

No

result:

ok answer is NO

Test #3:

score: 0
Accepted
time: 0ms
memory: 3884kb

input:

7 4
1 2 3 4 3 2 1
3 3 3 3

output:

Yes

result:

ok answer is YES

Test #4:

score: 0
Accepted
time: 0ms
memory: 3588kb

input:

5 1
5 4 3 2 1
10

output:

Yes

result:

ok answer is YES

Test #5:

score: -100
Time Limit Exceeded

input:

5000 5000
775487425 856128884 277783434 903422359 477267301 475103384 297595527 426167697 732858986 408894759 274205836 78265305 841664344 827278645 235744961 539622829 661053351 709331224 497285040 688977639 794889854 890450616 730989757 164925481 519732355 5132018 793806705 617096813 966338860 838...

output:


result: