Submission #858905

#	Time	Username	Problem	Language	Result	Execution time	Memory
858905		Ahmed57	Krov (COCI17_krov)	C++17	126 / 140	725 ms	35688 KiB

krov

#include <bits/stdc++.h>
#pragma GCC optimize ("trapv")
using namespace std;
int cn = 0;

struct lol{
long long sum[600001] = {0},cnt[600001] = {0};
void addSum(int e,int v){
    while(e<=cn){
        sum[e]+=v;
        e+=e&-e;
    }
}void addcnt(int e,int v){
    while(e<=cn){
        cnt[e]+=v;
        e+=e&-e;
    }
}long long querysum(int e){
    long long res = 0;
    while(e>=1){
        res+=sum[e];
        e-=e&-e;
    }
    return res;
}long long querycnt(int e){
    long long res = 0;
    while(e>=1){
        res+=cnt[e];
        e-=e&-e;
    }
    return res;
}
}pref,suf;
int main(){
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    int n;
    cin>>n;
    long long arr[n];
    for(int i = 0;i<n;i++){
        cin>>arr[i];
    }
    long long rev[n*3+1] = {0};
    map<int,int> sav;set<int> comp;
    vector<int> re,dr;
    for(int i = 0;i<n;i++){comp.insert(arr[i]-i);comp.insert(arr[i]+i);re.push_back(arr[i]+i);dr.push_back(arr[i]-i);dr.push_back(max(i+1,(n-i))-i);comp.insert(max(i+1,(n-i))-i);}
    for(auto i:comp){
        sav[i] = ++cn;
        rev[cn] = i;
    }
    long long val[n] = {0};
    for(int i = 0;i<n;i++){
        suf.addSum(sav[arr[i]+i],arr[i]+i);
        suf.addcnt(sav[arr[i]+i],1);
    }
    sort(re.begin(),re.end());
    sort(dr.begin(),dr.end());
    long long mi = 1e18;
    for(int i = 0;i<n;i++){
        suf.addSum(sav[arr[i]+i],-(arr[i]+i));
        suf.addcnt(sav[arr[i]+i],-1);
        pref.addSum(sav[arr[i]-i],arr[i]-i);
        pref.addcnt(sav[arr[i]-i],1);
        int ze = max(i+1,(n-i))-i;
        int l = 1, r = cn , ans = 0;
        l = lower_bound(dr.begin(),dr.end(),ze)-dr.begin();
        l = sav[dr[l]];
        while(l<=r){
            int mid = (l+r)/2;
            int it = lower_bound(re.begin(),re.end(),rev[mid]+2*i+1)-re.begin()-1;

            if(pref.querycnt(mid)+(it>=0?suf.querycnt(sav[re[it]]):0)>=(n+1)/2){
                ans = mid;
                r = mid-1;
            }else l = mid+1;
        }
        //cout<<rev[ans]<<" "<<pref.querycnt(ans)+suf.querycnt(ans+2*i)<<endl;
        long long CNT = pref.querycnt(ans) , SUM = pref.querysum(ans);
        long long lo = 0;
        lo+=(rev[ans])*CNT-SUM;
        CNT = pref.querycnt(cn)-CNT;
        SUM = pref.querysum(cn)-SUM;
        lo+=SUM-rev[ans]*CNT;
        //cout<<lo<<endl;
        int it = lower_bound(re.begin(),re.end(),rev[ans]+2*i+1)-re.begin()-1;
        int de = (it>=0?sav[re[it]]:0);
        CNT = suf.querycnt(de) , SUM = suf.querysum(de);
        lo+=(rev[ans]+2*i)*CNT-SUM;
        CNT = suf.querycnt(cn)-CNT;
        SUM = suf.querysum(cn)-SUM;
        lo+=SUM-(rev[ans]+2*i)*CNT;
        //cout<<lo<<endl;
        mi = min(mi,lo);
    }
    cout<<mi<<endl;
}
/*
4 5 7 2 2
pref : 4 4 5 -1 -2
suf : 4 6 9 5 6
rev[ans]+2*i
1: 5
2 , 3 , 4 , 5 : 3
*/

Compilation message (stderr)

krov.cpp: In function 'int main()':
krov.cpp:50:15: warning: unused variable 'val' [-Wunused-variable]
   50 |     long long val[n] = {0};
      |               ^~~

• Subtask 1: 14 / 14
• Subtask 2: 14 / 14
• Subtask 3: 14 / 14
• Subtask 4: 14 / 14
• Subtask 5: 14 / 14
• Subtask 6: 14 / 14
• Subtask 7: 14 / 14
• Subtask 8: 14 / 14
• Subtask 9: 14 / 14
• Subtask 10: 0 / 14