oj.uz

Submission #636708

# Submission time Handle Problem Language Result Execution time Memory
636708 2022-08-30T00:28:00 Z abeker Žarulje (COI15_zarulje) C++17
100 / 100
 348 ms 25196 KB 
#include <bits/stdc++.h>
using namespace std;

const int MAXN = 2e5 + 5;
const int MOD = 1e9 + 7;

int N, K;
vector <int> pos[MAXN];
int fact[MAXN], inv[MAXN];
int equal_lft[MAXN], equal_rig[MAXN];
int ans[MAXN];

void load() {
  scanf("%d%d", &N, &K);
  for (int i = 1; i <= N; i++) {
    int x;
    scanf("%d", &x);
    pos[x].push_back(i);
  }
}

inline int mul(int x, int y) {
  return (long long)x * y % MOD;
}

inline void mult(int &x, int y) {
  x = mul(x, y);
}

int pot(int x, int y) {
  int res = 1;
  for (; y; y /= 2) {
    if (y % 2)
      res = mul(res, x);
    x = mul(x, x);
  }
  return res;
}

void inc(int lo, int hi, int a, int b) {
  mult(ans[lo], mul(fact[a + b], mul(inv[a], inv[b])));
  mult(ans[hi], mul(mul(fact[a], fact[b]), inv[a + b]));
}

void solve() {
  fact[0] = inv[0] = 1;
  for (int i = 1; i <= N; i++) {
    fact[i] = mul(fact[i - 1], i);
    inv[i] = pot(fact[i], MOD - 2);
    ans[i] = 1;
  }
  set <int> sofar;
  for (int i = 1; i < MAXN; i++) {
    auto get_prev = [&](int x) {
      if (sofar.empty())
        return 0;
      auto it = sofar.lower_bound(x);
      return it == sofar.begin() ? 0 : *--it;
    };
    auto get_next = [&](int x) {
      if (sofar.empty())
        return N + 1;
      auto it = sofar.lower_bound(x + 1);
      return it == sofar.end() ? N + 1 : *it;
    };
    for (auto it : pos[i]) {
      auto count_equal = [&](int lo, int hi) {
        return lower_bound(pos[i].begin(), pos[i].end(), hi) - lower_bound(pos[i].begin(), pos[i].end(), lo);
      };
      equal_lft[it] = count_equal(get_prev(it) + 1, it + 1);
      equal_rig[it] = count_equal(it, get_next(it));
    }
    for (auto it : pos[i])
      sofar.insert(it);
    for (int j = 0; j < (int)pos[i].size() - 1; j++) {
      auto attempt = [&](int l, int r) {
        int tmp = get_next(l);
        if (tmp >= r)
          inc(l + 1, r, equal_lft[l], equal_rig[r]);
        else if (get_next(tmp) >= r)
          inc(tmp, tmp + 1, equal_lft[l], equal_rig[r]);
      };
      attempt(pos[i][j], pos[i][j + 1]);
      if (j < (int)pos[i].size() - 2)
        attempt(pos[i][j], pos[i][j + 2]);
    }
  }
  for (int i = 2; i <= N; i++)
    mult(ans[i], ans[i - 1]);
  while (K--) {
    int p;
    scanf("%d", &p);
    printf("%d ", ans[p]);
  }
  puts("");
}

int main() {
  load();
  solve();
  return 0;
}

Compilation message

zarulje.cpp: In function 'void load()':
zarulje.cpp:14:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |   scanf("%d%d", &N, &K);
      |   ~~~~~^~~~~~~~~~~~~~~~
zarulje.cpp:17:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |     scanf("%d", &x);
      |     ~~~~~^~~~~~~~~~
zarulje.cpp: In function 'void solve()':
zarulje.cpp:92:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   92 |     scanf("%d", &p);
      |     ~~~~~^~~~~~~~~~

Subtask #1
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 4 ms 5008 KB Output is correct
3 Correct 6 ms 5204 KB Output is correct
4 Correct 5 ms 5076 KB Output is correct
5 Correct 5 ms 5076 KB Output is correct
6 Correct 5 ms 5152 KB Output is correct

Subtask #2
38.0 / 38.0

# Verdict Execution time Memory Grader output
1 Correct 134 ms 12112 KB Output is correct
2 Correct 283 ms 19336 KB Output is correct
3 Correct 231 ms 19264 KB Output is correct
4 Correct 288 ms 19576 KB Output is correct
5 Correct 320 ms 19688 KB Output is correct
6 Correct 250 ms 21116 KB Output is correct
7 Correct 242 ms 22380 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 4 ms 5008 KB Output is correct
3 Correct 6 ms 5204 KB Output is correct
4 Correct 5 ms 5076 KB Output is correct
5 Correct 5 ms 5076 KB Output is correct
6 Correct 5 ms 5152 KB Output is correct
7 Correct 134 ms 12112 KB Output is correct
8 Correct 283 ms 19336 KB Output is correct
9 Correct 231 ms 19264 KB Output is correct
10 Correct 288 ms 19576 KB Output is correct
11 Correct 320 ms 19688 KB Output is correct
12 Correct 250 ms 21116 KB Output is correct
13 Correct 242 ms 22380 KB Output is correct
14 Correct 16 ms 5908 KB Output is correct
15 Correct 168 ms 13568 KB Output is correct
16 Correct 266 ms 22948 KB Output is correct
17 Correct 274 ms 21332 KB Output is correct
18 Correct 348 ms 23260 KB Output is correct
19 Correct 340 ms 21740 KB Output is correct
20 Correct 284 ms 23880 KB Output is correct
21 Correct 343 ms 25196 KB Output is correct