Submission #260184

#	Time	Username	Problem	Language	Result	Execution time	Memory
260184		sckmd	Vudu (COCI15_vudu)	C++14	140 / 140	444 ms	29524 KiB

vudu

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
#define MAXN 1000005
ll a[MAXN];
int bit[MAXN];
map <ll,int> mp;

void update(int idx,int val)
{
  while(idx < MAXN)
  {
    bit[idx] += val;
    idx += idx&(-idx);
  }
}
ll get(int idx)
{
  ll ret = 0LL;
  while(idx > 0)
  {
    ret += bit[idx];
    idx -= idx&(-idx);
  }
  return ret;
}
ll get(int l,int r)
{
  ll ret = get(r);
  if(l > 0)ret -= get(l-1);
  return ret;
}
vector <ll> all;
vector <ll> allz;
int main()
{
  ios_base::sync_with_stdio(false);
  int n;
  cin >> n;
  for(int i = 1; i <= n; i++)cin >> a[i];
  int p;
  cin >> p;
  for(int i = 1; i <= n; i++)a[i]-=p,a[i]+=a[i-1];
  allz.push_back(0);
  for(int i = 1; i <= n; i++)allz.push_back(a[i]);
  sort(allz.begin(),allz.end());
  ll prev = -1e18;
  for(auto x:allz)
  {
    if(x==prev)continue;
    all.push_back(x);
    prev=x;
  }
  ll ans = 0LL;
  for(int i = 0; i <= n; i++)
  {
    int idx = lower_bound(all.begin(),all.end(),a[i])-all.begin();
    idx++;
    ans += 1LL*get(idx);
    update(idx,1);
  }
  cout << ans;
  return 0;
}

• Subtask 1: 140 / 140