# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
260171 | sckmd | Vudu (COCI15_vudu) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define MAXN 1000005
ll a[MAXN];
ll bit[MAXN];
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;
}
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];
vector <int> all;
all.push_back(0);
for(int i = 1; i <= n; i++)all.push_back(a[i]);
sort(all.begin(),all.end());
erase(unique(all.begin(),all.end()),all.end());
for(int j = 0; j < all.size(); j++)
{
mp[all[j]]=j+1;
}
update(mp[0],1);
ll ans = 0LL;
for(int i = 1; i <= n; i++)
{
ans += get(mp[a[i]]);
update(mp[a[i]],1);
}
cout << ans;
return 0;
}