Submission #856766

#	Time	Username	Problem	Language	Result	Execution time	Memory
856766		Tenis0206	Climbers (RMI18_climbers)	C++11	60 / 100	206 ms	216912 KiB

climbers

#include <bits/stdc++.h>

using namespace std;

const unsigned int oo = 2 * INT_MAX;
const int nmax = 5e3;

int n;
int v[nmax + 5];

unsigned int d[nmax + 5][nmax + 5][2];

bool sel[nmax + 5][nmax + 5][2];

typedef pair<pair<unsigned int,int>,pair<int,int>> pii;

priority_queue<pii,vector<pii>,greater<pii>> h;

bool inclus(int a, int x, int y)
{
    if(x > y)
    {
        swap(x, y);
    }
    return (x <= a && a <= y);
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    #ifdef home
    freopen("nr.in","r",stdin);
    freopen("nr.out","w",stdout);
    #endif // home
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        cin>>v[i];
    }
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=n;j++)
        {
            d[i][j][0] = d[i][j][1] = oo;
        }
    }
    d[1][n][0] = d[1][n - 1][1] = 0;
    h.push({{0,0},{1,n}});
    h.push({{0,1},{1,n-1}});
    while(!h.empty())
    {
        while(!h.empty() && sel[h.top().second.first][h.top().second.second][h.top().first.second])
        {
            h.pop();
        }
        if(h.empty())
        {
            break;
        }
        int tip = h.top().first.second;
        int st = h.top().second.first;
        int dr = h.top().second.second;
        if(tip==0 && st==dr-1)
        {
            cout<<h.top().first.first<<'\n';
            return 0;
        }
        if(tip==1 && st==dr)
        {
            cout<<h.top().first.first<<'\n';
            return 0;
        }
        h.pop();
        sel[st][dr][tip] = true;
        if(tip==0)
        {
            /// st e intre pozitii

            /// st se duce la stanga, dr se duce la stanga
            if(dr!=1 && inclus(v[st], v[dr - 1], v[dr]))
            {
                if(d[st][dr][0] + abs(v[st] - v[dr]) < d[st][dr - 1][1])
                {
                    d[st][dr - 1][1] = d[st][dr][0] + abs(v[st] - v[dr]);
                    h.push({{d[st][dr - 1][1],1},{st, dr - 1}});
                }
            }

            /// st se duce la stanga, dr se duce la dreapta
            if(dr!=n && inclus(v[st], v[dr], v[dr + 1]))
            {
                if(d[st][dr][0] + abs(v[st] - v[dr]) < d[st][dr][1])
                {
                    d[st][dr][1] = d[st][dr][0] + abs(v[st] - v[dr]);
                    h.push({{d[st][dr][1],1},{st,dr}});
                }
            }

            /// st se duce la dreapta, dr se duce la stanga
            if(dr!=1 && inclus(v[st + 1], v[dr - 1], v[dr]))
            {
                if(d[st][dr][0] + abs(v[st + 1] - v[dr]) < d[st + 1][dr - 1][1])
                {
                    d[st + 1][dr - 1][1] = d[st][dr][0] + abs(v[st + 1] - v[dr]);
                    h.push({{d[st + 1][dr - 1][1], 1},{st + 1, dr - 1}});
                }
            }

            /// st se duce la dreapta, dr se duce la dreapta
            if(dr!=n && inclus(v[st + 1], v[dr], v[dr + 1]))
            {
                if(d[st][dr][0] + abs(v[st + 1] - v[dr]) < d[st + 1][dr][1])
                {
                    d[st + 1][dr][1] = d[st][dr][0] + abs(v[st + 1] - v[dr]);
                    h.push({{d[st + 1][dr][1], 1},{st + 1, dr}});
                }
            }

            /// dr se duce la stanga
            if(dr!=1 && inclus(v[dr - 1], v[st], v[st + 1]))
            {
                if(d[st][dr][0] + abs(v[dr - 1] - v[dr]) < d[st][dr - 1][0])
                {
                    d[st][dr - 1][0] = d[st][dr][0] + abs(v[dr - 1] - v[dr]);
                    h.push({{d[st][dr - 1][0], 0},{st,dr-1}});
                }
            }

            /// dr se duce la dreapta
            if(dr!=n && inclus(v[dr + 1], v[st], v[st + 1]))
            {
                if(d[st][dr][0] + abs(v[dr + 1] - v[dr]) < d[st][dr + 1][0])
                {
                    d[st][dr + 1][0] = d[st][dr][0] + abs(v[dr + 1] - v[dr]);
                    h.push({{d[st][dr + 1][0], 0},{st, dr + 1}});
                }
            }
        }
        else
        {
            /// dr e intre pozitii

            /// dr se duce la stanga, st se duce la stanga
            if(st!=1 && inclus(v[dr], v[st], v[st - 1]))
            {
                if(d[st][dr][1] + abs(v[dr] - v[st]) < d[st - 1][dr][0])
                {
                    d[st - 1][dr][0] = d[st][dr][1] + abs(v[dr] - v[st]);
                    h.push({{d[st - 1][dr][0], 0},{st - 1, dr}});
                }
            }

            /// dr se duce la stanga, st se duce la dreapta
            if(st!=n && inclus(v[dr], v[st], v[st + 1]))
            {
                if(d[st][dr][1] + abs(v[dr] - v[st]) < d[st][dr][0])
                {
                    d[st][dr][0] = d[st][dr][1] + abs(v[dr] - v[st]);
                    h.push({{d[st][dr][0],0},{st,dr}});
                }
            }

            /// dr se duce la dreapta, st se duce la stanga
            if(st!=1 && inclus(v[dr + 1], v[st],v[st - 1]))
            {
                if(d[st][dr][1] + abs(v[dr + 1] - v[st]) < d[st - 1][dr + 1][0])
                {
                    d[st - 1][dr + 1][0] = d[st][dr][1] + abs(v[dr + 1] - v[st]);
                    h.push({{d[st - 1][dr + 1][0], 0},{st - 1, dr + 1}});
                }
            }

            /// dr se duce la dreapta, st se duce la dreapta
            if(st!=n && inclus(v[dr + 1], v[st], v[st + 1]))
            {
                if(d[st][dr][1] + abs(v[dr + 1] - v[st]) < d[st][dr + 1][0])
                {
                    d[st][dr + 1][0] = d[st][dr][1] + abs(v[dr + 1] - v[st]);
                    h.push({{d[st][dr + 1][0], 0},{st, dr + 1}});
                }
            }

            /// st se duce la stanga
            if(st!=1 && inclus(v[st - 1], v[dr], v[dr + 1]))
            {
                if(d[st][dr][1] + abs(v[st - 1] - v[st]) < d[st - 1][dr][1])
                {
                    d[st - 1][dr][1] = d[st][dr][1] + abs(v[st - 1] - v[st]);
                    h.push({{d[st - 1][dr][1], 1},{st - 1, dr}});
                }
            }

            /// st se duce la dreapta
            if(st!=n && inclus(v[st + 1], v[dr], v[dr + 1]))
            {
                if(d[st][dr][1] + abs(v[st + 1] - v[st]) < d[st + 1][dr][1])
                {
                    d[st + 1][dr][1] = d[st][dr][1] + abs(v[st + 1] - v[st]);
                    h.push({{d[st + 1][dr][1], 1},{st + 1, dr}});
                }
            }
        }
    }
    cout<<"NO"<<'\n';
    return 0;
}

Compilation message (stderr)

climbers.cpp:5:27: warning: integer overflow in expression of type 'int' results in '-2' [-Woverflow]
    5 | const unsigned int oo = 2 * INT_MAX;
      |                           ^

• Subtask 1: 15 / 25
• Subtask 2: 25 / 25
• Subtask 3: 20 / 50