Submission #290181

#	Time	Username	Problem	Language	Result	Execution time	Memory
290181		SamAnd	Simurgh (IOI17_simurgh)	C++17	0 / 100	1429 ms	1048580 KiB

simurgh

#include "simurgh.h"
#include <bits/stdc++.h>
using namespace std;
#define m_p make_pair
#define fi first
#define se second
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
typedef long long ll;
const int N = 503;

int n, m;
int g[N][N];

vector<pair<int, int> > t[N];

bool c[N];
vector<int> r;
void dfs0(int x)
{
    c[x] = true;
    for (int h = 0; h < n; ++h)
    {
        if (!g[x][h])
            continue;
        if (c[h])
            continue;
        t[x].push_back(m_p(h, g[x][h] - 1));
        t[h].push_back(m_p(x, g[x][h] - 1));
        r.push_back(g[x][h] - 1);
        dfs0(h);
    }
}

vector<int> v;
bool dfs(int x, int p, int y)
{
    if (x == y)
        return true;
    for (int i = 0; i < t[x].size(); ++i)
    {
        int h = t[x][i].fi;
        v.push_back(t[x][i].se);
        if (dfs(h, x, y))
            return true;
        v.pop_back();
    }
}

std::vector<int> find_roads(int n_, std::vector<int> u_, std::vector<int> v_)
{
    n = n_;
    m = sz(u_);
    for (int i = 0; i < m; ++i)
    {
        int x = u_[i];
        int y = v_[i];
        g[x][y] = i + 1;
        g[y][x] = i + 1;
    }

    dfs0(1);
    int ans = count_common_roads(r);
    if (ans == n - 1)
        return r;

    for (int i = 0; i < m; ++i)
    {
        int x = u_[i];
        int y = v_[i];
        v.clear();
        dfs(x, x, y);
        if (sz(v) == 1)
            continue;
        for (int j = 0; j < sz(v); ++j)
        {
            vector<int> yr;
            for (int i = 0; i < n - 1; ++i)
            {
                if (r[i] == v[j])
                    continue;
                yr.push_back(r[i]);
            }
            yr.push_back(i);
            int yans = count_common_roads(yr);
            if (ans == yans)
                continue;
            if (ans < yans)
            {
                r = yr;
                ans = yans;
                if (ans == yans)
                    return r;
                for (int x = 0; x < n; ++x)
                {
                    t[x].clear();
                }
                for (int i = 0; i < n - 1; ++i)
                {
                    int x = u_[v[i]];
                    int y = v_[v[i]];
                    t[x].push_back(m_p(y, v[i]));
                    t[y].push_back(m_p(x, v[i]));
                }
            }
        }
    }
    assert(false);
}

Compilation message (stderr)

simurgh.cpp: In function 'bool dfs(int, int, int)':
simurgh.cpp:40:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |     for (int i = 0; i < t[x].size(); ++i)
      |                     ~~^~~~~~~~~~~~~
simurgh.cpp:48:1: warning: control reaches end of non-void function [-Wreturn-type]
   48 | }
      | ^

• Subtask 1: 0 / 13
• Subtask 2: 0 / 17
• Subtask 3: 0 / 21
• Subtask 4: 0 / 19
• Subtask 5: 0 / 30