Submission #976994

#	Time	Username	Problem	Language	Result	Execution time	Memory
976994		SeenSiravit	Vudu (COCI15_vudu)	C++14	56 / 140	317 ms	65536 KiB

vudu

#include<bits/stdc++.h>
#define ll long long

using namespace std;

const int mxN = 1e6 + 5;

struct DATA
{
    int idx;
    ll val;
};


int n;
ll a[mxN];
DATA b[mxN];
ll p;
int fw[mxN];
vector<DATA> tmp;
map<int,int> mp;

bool cmp(DATA x , DATA y){
    if(x.val == y.val) return x.idx < y.idx;
    return x.val < y.val;
}

void update(int idx , int val){
    for(int i=idx;i<mxN;i += (i & -i)) fw[i] += val;
}

ll query(int idx){
    ll res = 0;
    for(int i=idx;i>0;i -= (i & -i)) res += fw[i];
    return res;
}

int main(){
    ios::sync_with_stdio(0),cin.tie(0);
    
    cin>> n;

    for(int i=1;i<=n;i++) cin>> a[i] , a[i] += a[i-1];

    // for(int i=1;i<=n;i++) cout<< a[i] << " ";
    // cout<< "\n";

    cin>> p;

    for(int i=1;i<=n;i++) b[i].val = a[i] - p*i , b[i].idx = i , tmp.push_back(b[i]);
    // for(int i=1;i<=n;i++) cout<< b[i] << " ";
    // cout<< "\n\n";

    tmp.push_back({0,0});

    sort(tmp.begin() , tmp.end() , cmp);

    // for(auto elem : tmp) cout<< elem.idx << " " << elem.val << " , ";
    // cout<< "\n";

    int id = 1;
    for(auto elem : tmp){
        mp[elem.idx] = id;
        id++;
    }

    ll ans = 0;

    update(mp[0] , 1);

    for(int i=1;i<=n;i++){
        int cnt = query(mp[b[i].idx]);

        // cout<< "\ncnt = " << cnt << " ";

        // cout<< cnt << "\n\n";

        ans += cnt;

        update(mp[i] , 1);
    }

    cout<< ans;

    return 0;
}

• Subtask 1: 56 / 140