Submission #827067

#	Time	Username	Problem	Language	Result	Execution time	Memory
827067		tolbi	Shortcut (IOI16_shortcut)	C++17	31 / 100	2068 ms	352 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 crr = 0;
        ll leftside = 0;
        ll rightside = 0;
        for (int i = 0; i < n; i++){
            crr=max(crr,(ll)d[i]);
            for (int j = i+1; j < n; j++){
                ll cr1 = query(i,j);
                ll cr2 = query(l,i)+query(r,j)+c;
                cr2=min(cr2,query(r,i)+query(l,j)+c);
                crr=max(crr,min(cr1,cr2)+(ll)d[i]+(ll)d[j]);
                if (j>=r){
                    rightside=max(rightside,min(cr1,cr2)+(ll)d[i]+(ll)d[j]);
                }
                else {
                    leftside=max(leftside,min(cr1,cr2)+(ll)d[i]+(ll)d[j]);
                }
            }
        }
        pr={crr,(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: 9 / 9
• Subtask 2: 14 / 14
• Subtask 3: 8 / 8
• Subtask 4: 0 / 7
• Subtask 5: 0 / 33
• Subtask 6: 0 / 22
• Subtask 7: 0 / 4
• Subtask 8: 0 / 3