Submission #1084874

#	Time	Username	Problem	Language	Result	Execution time	Memory
1084874		guagua0407	Boxes with souvenirs (IOI15_boxes)	C++17	20 / 100	1 ms	356 KiB

boxes

#include "boxes.h"
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int,int>
#define f first
#define s second
#define all(x) x.begin(),x.end()
#define _ ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

long long delivery(int n, int k, int l, int p[]) {
    vector<pair<int,int>> vec;
    for(int i=0;i<n;i++){
        if(vec.empty() or p[i]!=vec.back().f){
            vec.push_back({p[i],1});
        }
        else{
            auto pp=vec.back();
            vec.pop_back();
            vec.push_back({pp.f,pp.s+1});
        }
    }
    auto rec=vec;
    int pos=-1;
    int sz=(int)vec.size();
    for(int i=0;i<sz;i++){
        if(vec[i].f<(l+1)/2){
            pos=i;
        }
    }
    ll res;
    {
        ll ans=0;
        int last1=0,last2=0;
        if(pos!=-1){
            int cur=0;
            while(cur<=pos){
                int left=k;
                int mx=vec[cur].f;
                while(cur<=pos and left>0){
                    int prv=vec[cur].s;
                    vec[cur].s=max(0,vec[cur].s-left);
                    left-=(prv-vec[cur].s);
                    mx=vec[cur].f;
                    if(vec[cur].s==0) cur++;
                }
                last1=k-left;
                ans+=2*mx;
            }
        }
        if(pos<sz-1){
            int cur=sz-1;
            while(cur>pos){
                int left=k;
                int mn=vec[cur].f;
                while(cur>pos and left>0){
                    int prv=vec[cur].s;
                    vec[cur].s=max(0,vec[cur].s-left);
                    left-=(prv-vec[cur].s);
                    mn=vec[cur].f;
                    if(vec[cur].s==0) cur--;
                }
                last2=k-left;
                ans+=2*(l-mn);
            }
        }
       if(last1+last2<=k){
            ll tmp=ans;
            if(pos>=0){
                tmp-=2*vec[pos].f;
            }
            if(pos<sz-1){
                tmp-=2*(l-vec[pos+1].f);
            }
            tmp+=l;
            ans=min(ans,tmp);
       }
       res=ans;
    }
    vec=rec;
    if(pos>=0){
        pos--;
        ll ans=0;
        int last1=0,last2=0;
        if(pos!=-1){
            int cur=0;
            while(cur<=pos){
                int left=k;
                int mx=vec[cur].f;
                while(cur<=pos and left>0){
                    int prv=vec[cur].s;
                    vec[cur].s=max(0,vec[cur].s-left);
                    left-=(prv-vec[cur].s);
                    mx=vec[cur].f;
                    if(vec[cur].s==0) cur++;
                }
                last1=k-left;
                ans+=2*mx;
            }
        }
        if(pos<sz-1){
            int cur=sz-1;
            while(cur>pos){
                int left=k;
                int mn=vec[cur].f;
                while(cur>pos and left>0){
                    int prv=vec[cur].s;
                    vec[cur].s=max(0,vec[cur].s-left);
                    left-=(prv-vec[cur].s);
                    mn=vec[cur].f;
                    if(vec[cur].s==0) cur--;
                }
                last2=k-left;
                ans+=2*(l-mn);
            }
        }
       if(last1+last2<=k){
            ll tmp=ans;
            if(pos>=0){
                tmp-=2*vec[pos].f;
            }
            if(pos<sz-1){
                tmp-=2*(l-vec[pos+1].f);
            }
            tmp+=l;
            ans=min(ans,tmp);
       }
       res=min(res,ans);
       pos++;
    }
    vec=rec;
    if(pos<sz-1){
        pos++;
        ll ans=0;
        int last1=0,last2=0;
        if(pos!=-1){
            int cur=0;
            while(cur<=pos){
                int left=k;
                int mx=vec[cur].f;
                while(cur<=pos and left>0){
                    int prv=vec[cur].s;
                    vec[cur].s=max(0,vec[cur].s-left);
                    left-=(prv-vec[cur].s);
                    mx=vec[cur].f;
                    if(vec[cur].s==0) cur++;
                }
                last1=k-left;
                ans+=2*mx;
            }
        }
        if(pos<sz-1){
            int cur=sz-1;
            while(cur>pos){
                int left=k;
                int mn=vec[cur].f;
                while(cur>pos and left>0){
                    int prv=vec[cur].s;
                    vec[cur].s=max(0,vec[cur].s-left);
                    left-=(prv-vec[cur].s);
                    mn=vec[cur].f;
                    if(vec[cur].s==0) cur--;
                }
                last2=k-left;
                ans+=2*(l-mn);
            }
        }
       if(last1+last2<=k){
            ll tmp=ans;
            if(pos>=0){
                tmp-=2*vec[pos].f;
            }
            if(pos<sz-1){
                tmp-=2*(l-vec[pos+1].f);
            }
            tmp+=l;
            ans=min(ans,tmp);
       }
       res=min(res,ans);
    }
    return res;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30