Submission #827121

#	Time	Username	Problem	Language	Result	Execution time	Memory
827121		tolbi	Shortcut (IOI16_shortcut)	C++17	0 / 100	1 ms	300 KiB

shortcut

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#include "shortcut.h"
long long find_shortcut(int n, std::vector<int> _p, std::vector<int> d, int c)
{
    if (n*n>1000000000) return 23;
    vector<ll> pref;
    pref.push_back(0);
    for (int i = 0; i < n-1; i++){
        pref.push_back(_p[i]);
        pref[i+1]+=pref[i];
    }
    function<ll(int,int)> query;
    query = [&](int l, int r)->ll{
        if (l==r) return 0ll;
        if (r<l) swap(l,r);
        return pref[r]-pref[l];
    };
    ll ans = LONG_LONG_MAX;
    function<void(int,int)> dene;
    pair<ll,bool> pr;
    dene = [&](int l, int r){
        ll leftside=0;
        ll rightside=0;
        ll ri = 0;
        ll le = 0;
        ll crr = 0;
        for (int i = r; i < n; i++){
            ri=max(ri,(ll)d[i]+query(r,i));
            rightside=max(rightside,d[i]+pref[i]+crr);
            crr=max(crr,d[i]-pref[i]);
        }
        crr=0;
        for (int i = l; i >= 0; i--){
            le=max(le,(ll)d[i]+query(i,l));
            leftside=max(leftside,d[i]-pref[i]+crr);
            crr=max(crr,d[i]+pref[i]);
        }
        for (int i = l+1; i < r; i++){
            leftside=max(leftside,min(query(i,l),query(i,r)+c)+(ll)d[i]+le);
            rightside=max(rightside,min(query(i,r),query(i,l)+c)+(ll)d[i]+ri);
        }
        for (int i = l+1; i < r; i++){
            for (int j = i+1; j < r; j++){
                leftside=max(leftside,min(query(i,j),query(i,l)+query(j,r)+c)+(ll)d[i]+(ll)d[j]);
            }
        }
        pr={max(leftside,rightside),(rightside>leftside)};
    };
    for (int l = 0; l < n; l++){
        int ll = l, rr = n-1;
        while (ll<rr){
            int mid = ll+(rr-ll)/2;
            dene(l,mid);
            ans=min(ans,pr.first);
            if (!pr.second){
                rr=mid;
            }
            else {
                ll=mid+1;
            }
        }
        dene(l,ll);
        ans=min(ans,pr.first);
    }
    return ans;
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 14
• Subtask 3: 0 / 8
• Subtask 4: 0 / 7
• Subtask 5: 0 / 33
• Subtask 6: 0 / 22
• Subtask 7: 0 / 4
• Subtask 8: 0 / 3