Submission #877119

#	Time	Username	Problem	Language	Result	Execution time	Memory
877119		MarwenElarbi	Sails (IOI07_sails)	C++17	100 / 100	80 ms	3988 KiB

sails

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ii = pair<int, int>;

#define foru(i, l, r) for(int i=(l); i<=(r); ++i)
#define ford(i, l, r) for(int i=(l); i>=(r); --i)
#define fore(x, v) for(auto &x : v)
#define fi first
#define se second

void setIO(string name) {
  ios::sync_with_stdio(0);
  cin.tie(0); cout.tie(0);
  if (!name.empty()) {
    freopen((name + ".in").c_str(), "r", stdin);
    freopen((name + ".out").c_str(), "w", stdout);
  }
}

const int N = 1e5+5, V = 1e5;
const int LOG = 17;

int n;
ll ans, bit[2][N];
ii mast[N];

void modify(int t, int i, ll v) { 
  for(; i<=V; i+=i&-i) bit[t][i] += v;
}

ll get(int t, int i) {
  ll ans = 0;
  for(; i>=1; i-=i&-i) ans += bit[t][i];
  return ans;
}

void inc(int l, int r, ll v) {
  modify(0, l, v);
  modify(0, r+1, -v);
  modify(1, l, v * (l-1));
  modify(1, r+1, - v * r);
}

ll sum_range(ll i) {
  return get(0, i) * i - get(1, i);
}

ll sum_range(int l, int r) {
  return sum_range(r) - sum_range(l-1);
}

int lst(int val) {
  int cur = 0, till = 0;
  for(int i=LOG-1; i>=0; --i)
    if (cur+(1<<i) <= V && till+bit[0][cur+(1<<i)] <= val)
      cur += 1 << i, till += bit[0][cur];
  return cur;
}

int main() {
  cin >> n;

  foru(i, 1, n) {
    cin >> mast[i].fi >> mast[i].se;
  }

  sort(mast+1, mast+n+1);

  foru(i, 1, n) {
    int hei = mast[i].fi, cnt = mast[i].se;
    int lb = V-hei+1, alpha = get(0, min(V, lb+cnt-1));
    int rb = lst(alpha), rx = max(lb-1, lst(alpha-1)), lx = max(rx+1, rb-(cnt-(rx-lb+1))+1);
    ans += sum_range(lb, rx); 
    ans += sum_range(lx, rb);
    inc(lb, rx, 1);
    inc(lx, rb, 1);
  }

  cout << ans;
}

Compilation message (stderr)

sails.cpp: In function 'void setIO(std::string)':
sails.cpp:16:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     freopen((name + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sails.cpp:17:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |     freopen((name + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 5 / 5
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10
• Subtask 11: 10 / 10