Submission #411266

#	Time	Username	Problem	Language	Result	Execution time	Memory
411266		LouayFarah	Crocodile's Underground City (IOI11_crocodile)	C++14	0 / 100	1 ms	204 KiB

crocodile

#include "bits/stdc++.h"
#include "crocodile.h"
using namespace std;
 
#define fi first
#define se second
#define pb push_back
#define mp make_pair
 
void dfs(vector<pair<int, int>> tree[], vector<int> &parent, vector<int> &dist, vector<int> &len, int u, int e)
{
    for(auto v: tree[u])
    {
        if(v.fi==e)
            continue;
        parent[v.fi] = u;
        dist[v.fi] = dist[u] + v.se;
        len[v.fi] = len[u] + 1;
        dfs(tree, parent, dist, len, v.fi, u);
    }
}
 
void remove_subtree(vector<pair<int, int>> tree[], vector<bool> &erased, int u, int e)
{
    erased[u] = true;
    for(auto v: tree[u])
        if(v.fi!=e)
            remove_subtree(tree, erased, v.fi, u);
}
 
int travel_plan(int n, int m, int r[][2], int l[], int k, int p[])
{
    vector<pair<int, int>> tree[n];
    for(int i = 0; i<m; i++)
    {
        tree[r[i][0]].pb(mp(r[i][1], l[i]));
        tree[r[i][1]].pb(mp(r[i][0], l[i]));
    }
 
    vector<int> dist(n, 0);
    vector<int> len(n, 0);
    vector<int> parent(n, -1);
    dfs(tree, parent, dist, len, 0, -1);
 
    vector<pair<pair<int, int>, int>> arr;
    for(int i = 0; i<k; i++)
    {
        arr.pb(mp(mp(dist[p[i]], len[p[i]]), p[i]));
    }
 
    sort(arr.begin(), arr.end());
 
    vector<bool> erased(n, false);
 
    int res = 0;
    /*for(int i = 0; i<k; i++)
        cout << arr[i].fi.fi << ' ' << arr[i].fi.se << ' ' << arr[i].se << endl;*/
 
    sort(p, p+k);
    for(int i = 0; i<k; i++)
    {
        if(erased[arr[i].se])
            continue;
        if(i+1<arr[i].fi.se)
        {
            remove_subtree(tree, erased, parent[arr[i].se], parent[parent[arr[i].se]]);
        }
        else if(i+1==arr[i].fi.se)
        {
            vector<int> temp;
            for(auto u: tree[parent[arr[i].se]])
            {
                if(binary_search(p, p+k, u.fi))
                    temp.pb(dist[u.fi]);
            }
            if(temp.size()>1)
            {
                sort(temp.begin(), temp.end());
                res = temp[1];
                break;
            }
        }
        else
        {
            res = arr[i].fi.fi;
            break;
        }
    }
 
    return res;
}

• Subtask 1: 0 / 46
• Subtask 2: 0 / 43
• Subtask 3: 0 / 11