Submission #1093821

#	Time	Username	Problem	Language	Result	Execution time	Memory
1093821		ASN49K	Climbers (RMI18_climbers)	C++14	45 / 100	149 ms	196076 KiB

climbers

#include <bits/stdc++.h>
using namespace std;
using i64=long long;
#define UNUSED -1
#define all(x) x.begin(),x.end()
#define pb push_back
const int mod=1e9+7,inf=1e9+1;
const i64 INF=1e18;
struct node
{
    int nod1,nod2;
    long long cost;

    bool operator <(const node& b) const
    {
        return cost>b.cost;
    }
};

bool same_type_diff(int a,int b,int c)
{
    return (a<b && b<c) || (a>b && b>c);
}
void modify_h(vector<int>&h)
{
    vector<int>sol;
    for(auto &c:h)
    {
        while(sol.size()>=2 && (sol.back()==c || same_type_diff(sol[sol.size()-2],sol.back(),c)))
        {
            sol.pop_back();
        }
        sol.push_back(c);
    }
    h=sol;
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin>>n;
    vector<int>h(n);
    for(auto &c:h)
    {
        cin>>c;
    }
    modify_h(h);
    n=(int)h.size();
    priority_queue<node>q;
    vector<vector<i64>>dist(n,vector<i64>(n-1,INF));
    dist[0][n-2]=0;
    q.push({0,n-2,0});
    auto add=[&](int x,int y,i64 cost)
    {
        if(dist[x][y]>cost)
        {
            dist[x][y]=cost;
            q.push({x,y,cost});
        }
    };
    while(q.size())
    {
        auto then=q.top();
        q.pop();
        int nod1=then.nod1,nod2=then.nod2;
        if(then.cost != dist[nod1][nod2])
        {
            continue;
        }
        if(nod1==nod2 || nod1==nod2+1)
        {
            cout<<then.cost;
            return 0;
        }


        int capat_min=min(h[nod2],h[nod2+1]);
        int capat_max=max(h[nod2],h[nod2+1]);
        int capat_min_poz=nod2;
        int capat_max_poz=nod2+1;
        if(capat_min!=h[capat_min_poz])
        {
            swap(capat_min_poz,capat_max_poz);
        }


        //e minim local
        if(nod1==0 || h[nod1]<h[nod1-1])
        {
            //merg spre nod1-1
            if(nod1>0)
            {
                int minn=min(h[nod1-1] , capat_max);
                if(minn==h[nod1-1])
                {
                    add(nod1-1,nod2,then.cost+abs(minn-h[nod1]));
                }
                if(minn==capat_max)
                {
                    add(capat_max_poz,nod1-1,then.cost+abs(minn-h[nod1]));
                }
            }
            if(nod1<n-1)
            {
                int minn=min(h[nod1+1] , capat_max);
                if(minn==h[nod1+1])
                {
                    add(nod1+1,nod2,then.cost+abs(minn-h[nod1]));
                }
                if(minn==capat_max)
                {
                    add(capat_max_poz,nod1,then.cost+abs(minn-h[nod1]));
                }
            }
        }
        else
        {
            if(nod1>0)
            {
                int minn=max(h[nod1-1] , capat_min);
                if(minn==h[nod1-1])
                {
                    add(nod1-1,nod2,then.cost+abs(minn-h[nod1]));
                }
                if(minn==capat_min)
                {
                    add(capat_min_poz,nod1-1,then.cost+abs(minn-h[nod1]));
                }
            }
            if(nod1<n-1)
            {
                int minn=max(h[nod1+1] , capat_min);
                if(minn==h[nod1+1])
                {
                    add(nod1+1,nod2,then.cost+abs(minn-h[nod1]));
                }
                if(minn==capat_min)
                {
                    add(capat_min_poz,nod1,then.cost+abs(minn-h[nod1]));
                }
            }
        }
    }
    cout<<"NO";
}

• Subtask 1: 25 / 25
• Subtask 2: 15 / 25
• Subtask 3: 5 / 50