Submission #319712

#	Time	Username	Problem	Language	Result	Execution time	Memory
319712		alextodoran	Stations (IOI20_stations)	C++17	100 / 100	1075 ms	1248 KiB

stations

/**
 ____ ____ ____ ____ ____
||a |||t |||o |||d |||o ||
||__|||__|||__|||__|||__||
|/__\|/__\|/__\|/__\|/__\|

**/

#include <bits/stdc++.h>
#include "stations.h"

using namespace std;

const int N_MAX = 1002;

vector <int> edges[N_MAX];

int sub[N_MAX];

void dfs (int u, int parent = -1)
{
    sub[u] = 1;
    for(int v : edges[u])
        if(v != parent)
        {
            dfs(v, u);
            sub[u] += sub[v];
        }
}

int lb[N_MAX];

void solve (int u, int l, int r, bool type, int parent = -1)
{
    if(type == 0)
        lb[u] = l++;
    else
        lb[u] = r--;
    for(int v : edges[u])
        if(v != parent)
        {
            solve(v, l, l + sub[v] - 1, !type, u);
            l += sub[v];
        }
}

vector <int> label (int n, int k, vector <int> u, vector <int> v)
{
    for(int i = 1; i < n; i++)
    {
        int a = u[i - 1] + 1;
        int b = v[i - 1] + 1;
        edges[a].push_back(b);
        edges[b].push_back(a);
    }
    dfs(1);
    solve(1, 1, n, 0);
	vector <int> labels(n);
    for(int i = 1; i <= n; i++)
        labels[i - 1] = lb[i] - 1;
    for(int i = 1; i <= n; i++)
        edges[i].clear();
	return labels;
}

int find_next_station (int s, int t, vector <int> c)
{
    bool type = 1;
    for(int u : c)
        type &= (u < s);
    if(type == 0)
    {
        sort(c.begin(), c.end());
        int root = c.back();
        c.pop_back();
        int l = s + 1;
        for(int u : c)
        {
            if(l <= t && t <= u)
                return u;
            l = u + 1;
        }
        return root;
    }
    else
    {
        sort(c.begin(), c.end());
        reverse(c.begin(), c.end());
        int root = c.back();
        c.pop_back();
        int r = s - 1;
        for(int u : c)
        {
            if(u <= t && t <= r)
                return u;
            r = u - 1;
        }
        return root;
    }
}

Compilation message (stderr)

stations.cpp: In function 'std::vector<int> label(int, int, std::vector<int>, std::vector<int>)':
stations.cpp:61:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   61 |     for(int i = 1; i <= n; i++)
      |     ^~~
stations.cpp:63:2: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   63 |  return labels;
      |  ^~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 16 / 16
• Subtask 4: 10 / 10
• Subtask 5: 61 / 61