Submission #901903

#	Time	Username	Problem	Language	Result	Execution time	Memory
901903		nguyentunglam	Dancing Elephants (IOI11_elephants)	C++17	26 / 100	9063 ms	58252 KiB

elephants

#include<bits/stdc++.h>
#define fi first
#define se second
#define endl "\n"
#define ii pair<int, int>
using namespace std;

const int N = 1e5 + 10, T = 1e3, _T = 1e9 / T;

int n, l;

int a[N], b[N];

vector<pair<int, int> > f[_T];

vector<int> arr[_T];

void add_block (int block, int x) {
  for(int i = 0; i < arr[block].size(); i++) if (arr[block][i] >= x) {
    arr[block].insert(arr[block].begin() + i, x);
    return;
  }
  arr[block].push_back(x);
}

void del_block (int block, int x) {
  for(int i = 0; i < arr[block].size(); i++) if (arr[block][i] == x) {
    arr[block].erase(arr[block].begin() + i);
    return;
  }
}

void update_block (int block) {
  f[block].resize(arr[block].size());
  for(int i = arr[block].size() - 1, j = arr[block].size(); i >= 0; i--) {
    while (j > 0 && arr[block][j - 1] - l > arr[block][i]) {
      j--;
    }
    if (j == arr[block].size()) f[block][i] = make_pair(1, arr[block][i]);
    else f[block][i] = make_pair(f[block][j].first + 1, f[block][j].second);
  }
}

void init(int N, int L, int X[])
{
  n = N; l = L;

  for(int i = 0; i < n; i++) a[i] = X[i];

  for(int i = 0; i < n; i++) arr[a[i] / T].push_back(a[i]);

  for(int block = 0; block < _T; block++) if (!arr[block].empty()) {
    sort(arr[block].begin(), arr[block].end());
    update_block (block);
  }
}

int get () {
  int last = -1e9, ans = 0;
  for(int block = 0; block < _T; block++) if (!arr[block].empty()) {
    int x = upper_bound(arr[block].begin(), arr[block].end(), last + l) - arr[block].begin();
    if (x < arr[block].size()) {
      ans += f[block][x].first;
      last = f[block][x].second;
    }
  }
  return ans;
}

int update(int i, int y)
{
  del_block(a[i] / T, a[i]);
  update_block(a[i] / T);
  a[i] = y;
  add_block(a[i] / T, a[i]);
  update_block(a[i] / T);

  return get();
}

#ifdef ngu
int x[N];
int main() {

  freopen ("task.inp", "r", stdin);
  freopen ("task.out", "w", stdout);

  int n, l, m; cin >> n >> l >> m;

  for(int i = 0; i < n; i++) cin >> x[i];

  init(n, l, x);

  while (m--) {
    int i, v; cin >> i >> v;
    cout << update(i, v) << endl;
  }
}
#endif // ngu

Compilation message (stderr)

elephants.cpp: In function 'void add_block(int, int)':
elephants.cpp:19:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |   for(int i = 0; i < arr[block].size(); i++) if (arr[block][i] >= x) {
      |                  ~~^~~~~~~~~~~~~~~~~~~
elephants.cpp: In function 'void del_block(int, int)':
elephants.cpp:27:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |   for(int i = 0; i < arr[block].size(); i++) if (arr[block][i] == x) {
      |                  ~~^~~~~~~~~~~~~~~~~~~
elephants.cpp: In function 'void update_block(int)':
elephants.cpp:39:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |     if (j == arr[block].size()) f[block][i] = make_pair(1, arr[block][i]);
      |         ~~^~~~~~~~~~~~~~~~~~~~
elephants.cpp: In function 'int get()':
elephants.cpp:62:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |     if (x < arr[block].size()) {
      |         ~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 16 / 16
• Subtask 3: 0 / 24
• Subtask 4: 0 / 47
• Subtask 5: 0 / 3