제출 #94477

#제출 시각아이디문제언어결과실행 시간메모리
94477theknife2001Vudu (COCI15_vudu)C++11
42 / 140
1080 ms66560 KiB
#include <bits/stdc++.h>
#define ll long long
#define mid (l+r)/2

using namespace std;
map < ll , int > mp;
const int N=1e6+55;
short tree[N*4];
ll sum[N];
ll a[N];
int n;

void update(int node , int l , int r , int ind)
{
    if(l==r&&l==ind)
    {
        tree[node]++;
        return ;
    }
    if(ind<=mid)
        update(node*2,l,mid,ind);
    else
        update(node*2+1,mid+1,r,ind);
    tree[node]=tree[node*2]+tree[node*2+1];
}

int query(int node  , int l , int r , int x , int y)
{
    if(x<=l&&r<=y)
        return tree[node];
    if(l>y||r<x)
        return 0;
    return query(node*2,l,mid,x,y)+query(node*2+1,mid+1,r,x,y);
}

int main()
{
    cin>>n;
    for(int i=0;i<n;i++)
        cin>>a[i];
    int p;
    cin>>p;
    for(int i=n-1;i>=0;i--)
    {
        sum[i]=a[i]-p;
        if(i!=n-1)
            sum[i]+=sum[i+1];
        a[i]=sum[i];
    }
    sort(a,a+n);
    int cnt=1;
    for(int i=0;i<n;i++)
    {
        if(mp[a[i]]==0)
            mp[a[i]]=cnt++;
    }
    ll ans=0;
    for(int i=n-1;i>=0;i--)
    {
        if(sum[i]>=0)
            ans++;
        ans+=query(1,0,1e6,0,mp[sum[i]]);
        update(1,0,1e6,mp[sum[i]]);
    }
    cout<<ans<<endl;
    return 0;
}
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