oj.uz

Submission #1009340

# Submission time Handle Problem Language Result Execution time Memory
1009340 2024-06-27T11:43:38 Z boris_mihov Simurgh (IOI17_simurgh) C++17
30 / 100
 202 ms 134992 KB 
#include "simurgh.h"
#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <cstring>
#include <vector>

typedef long long llong;
const int MAXN = 500 + 12;

namespace
{
    int n;
    int dep[MAXN];
    int par[MAXN];
    bool vis[MAXN];
    int idx[MAXN][MAXN];
    int covering[MAXN][MAXN];
    bool queried[MAXN][MAXN];
    bool isIn[MAXN][MAXN];
    bool isInTree[MAXN][MAXN];
    std::vector <int> g[MAXN];
    std::vector <int> t[MAXN];
    std::vector <std::pair <int,int>> byCovering[MAXN * MAXN];
    std::vector <std::pair <int,int>> inTreeEdges;
    std::vector <int> inTree;
}

struct DSU
{
    int par[MAXN];
    int dep[MAXN];

    void reset()
    {
        std::iota(par, par + n, 0);
        std::fill(dep, dep + n, 1);
    }

    int find(int node)
    {
        if (par[node] == node) return node;
        return par[node] = find(par[node]);
    }

    void connect(int u, int v)
    {
        u = find(u);
        v = find(v);
        assert(u != v);

        if (u == v)
        {
            return;
        }

        if (dep[u] > dep[v])
        {
            std::swap(u, v);
        }

        if (dep[u] == dep[v])
        {
            dep[v]++;
        }

        par[u] = v;
    }

    bool areConnected(int u, int v)
    {
        return find(u) == find(v);
    }
};

DSU dsu;
void depthDFS(int node, int p)
{
    par[node] = p;
    vis[node] = true;
    for (const int &u : g[node])
    {
        if (u == p || vis[u])
        {
            continue;
        }

        dep[u] = dep[node] + 1;
        t[node].push_back(u);
        isInTree[node][u] = true;
        isInTree[u][node] = true;
        inTree.push_back(idx[u][node]);
        inTreeEdges.push_back({u, node});
        depthDFS(u, node);
    }
}

void apply(int u, int v, int idx)
{
    if (u == v)
    {
        return;
    }

    byCovering[idx].push_back({u, par[u]});
    covering[u][par[u]] = idx;
    apply(par[u], v, idx);
}

void dfsCovering(int node)
{
    if (node != 0)
    {
        if (covering[node][par[node]] == -1) 
        {
            isIn[node][par[node]] = true;
            isIn[par[node]][node] = true;
        }
    }

    for (const int &u : t[node])
    {
        dfsCovering(u);
    }
}

int treeIncluding(std::vector <std::pair <int,int>> &edges)
{
    dsu.reset();
    std::vector <int> indices;
    // std::cout << "tree including:\n";
    // for (const auto &[u, v] : edges)
    // {
    //     std::cout << u << ' ' << v << '\n';
    // }

    // std::cout << std::flush;
    for (const auto &[u, v] : edges)
    {
        assert(!dsu.areConnected(u, v));
        dsu.connect(u, v);
        indices.push_back(idx[u][v]);
    }

    int sub = 0;
    for (const auto &[u, v] : inTreeEdges)
    {
        if (dsu.areConnected(u, v))
        {
            continue;
        }

        sub += isIn[u][v];
        indices.push_back(idx[u][v]);
        dsu.connect(u, v);
    }  

    return count_common_roads(indices) - sub;
}

std::vector <int> find_roads(int n, std::vector <int> u, std::vector <int> v) 
{ 
    ::n = n;
    memset(idx, -1, sizeof(idx));
    memset(covering, -1, sizeof(idx));
    for (int i = 0 ; i < u.size() ; ++i)
    {
        idx[u[i]][v[i]] = i;
        idx[v[i]][u[i]] = i;
        g[u[i]].push_back(v[i]);
        g[v[i]].push_back(u[i]);
    }

    depthDFS(0, -1);
    // std::cout << "in tree\n";
    // for (const auto &[u, v] : inTreeEdges)
    // {
    //     std::cout << u << ' ' << v << '\n';
    // }

    for (int i = 0 ; i < u.size() ; ++i)
    {
        if (isInTree[u[i]][v[i]])
        {
            continue;
        }

        if (dep[u[i]] > dep[v[i]]) apply(u[i], v[i], i);
        else apply(v[i], u[i], i);
    }

    dfsCovering(0);
    int globalTreeCount = count_common_roads(inTree);
    if (globalTreeCount == n - 1)
    {
        return inTree;
    }

    for (int coverIdx = 0 ; coverIdx < u.size() ; ++coverIdx)
    {
        if (byCovering[coverIdx].empty())
        {
            continue;
        }

        int res = globalTreeCount;
        std::vector <int> sols;
        bool foundMAX = false;
        for (int i = 0 ; i < byCovering[coverIdx].size() ; ++i)
        {
            if (queried[byCovering[coverIdx][i].first][byCovering[coverIdx][i].second] && (foundMAX || !isIn[byCovering[coverIdx][i].first][byCovering[coverIdx][i].second]))
            {
                sols[i] = MAXN;
                continue;
            }

            std::vector <int> curr = inTree;
            for (int &j : curr)
            {
                if (j == idx[byCovering[coverIdx][i].first][byCovering[coverIdx][i].second])
                {
                    std::swap(j, curr.back());
                    curr.pop_back();
                    break;
                }
            }

            curr.push_back(coverIdx);
            sols.push_back(count_common_roads(curr));
            res = std::max(res, sols.back());

            if (queried[byCovering[coverIdx][i].first][byCovering[coverIdx][i].second])
            {
                foundMAX = true;
            }
        }

        // std::cout << "here: " << coverIdx << ' ' << byCovering[coverIdx].size() << '\n';
        for (int i = 0 ; i < byCovering[coverIdx].size() ; ++i)
        {
            // std::cout <<
            if (sols[i] < res)
            {
                // std::cout << "in golden set: " << byCovering[coverIdx][i].first << ' ' << byCovering[coverIdx][i].second << '\n';
                isIn[byCovering[coverIdx][i].first][byCovering[coverIdx][i].second] = true;
                isIn[byCovering[coverIdx][i].second][byCovering[coverIdx][i].first] = true;
            }
        }
    }

    for (int u = 0 ; u < n ; ++u)
    {
        std::vector <std::pair <int,int>> allEdges;
        for (const int &v : g[u])
        {
            if (isInTree[u][v] || v < u)
            {
                continue;
            }

            allEdges.push_back({u, v});
        }

        int lastPos = -1;
        int countFound = 0;
        int cnt = treeIncluding(allEdges);
        // std::cout << "cnt for: " << u << " = " << cnt << '\n';
        while (cnt--)
        {
            int l = lastPos, r = allEdges.size(), mid;
            while (l < r - 1)
            {
                mid = l + r >> 1;
                std::vector <std::pair <int,int>> curr;
                for (int i = 0 ; i <= mid ; ++i)
                {
                    curr.push_back(allEdges[i]);
                }

                if (treeIncluding(curr) <= countFound) l = mid;
                else r = mid;
            }

            assert(r < allEdges.size());
            isIn[u][allEdges[r].second] = true;
            isIn[allEdges[r].second][u] = true;
            countFound++;
            lastPos = r;
        }
    }

    std::vector <int> sol;
    for (int i = 0 ; i < n ; ++i)
    {
        for (int j = i + 1 ; j < n ; ++j)
        {
            if (isIn[i][j])
            {
                sol.push_back(idx[i][j]);
            }
        }
    }

    return sol;
}

Compilation message

simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:167:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  167 |     for (int i = 0 ; i < u.size() ; ++i)
      |                      ~~^~~~~~~~~~
simurgh.cpp:182:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  182 |     for (int i = 0 ; i < u.size() ; ++i)
      |                      ~~^~~~~~~~~~
simurgh.cpp:200:38: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  200 |     for (int coverIdx = 0 ; coverIdx < u.size() ; ++coverIdx)
      |                             ~~~~~~~~~^~~~~~~~~~
simurgh.cpp:210:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  210 |         for (int i = 0 ; i < byCovering[coverIdx].size() ; ++i)
      |                          ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
simurgh.cpp:240:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  240 |         for (int i = 0 ; i < byCovering[coverIdx].size() ; ++i)
      |                          ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
simurgh.cpp:274:25: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  274 |                 mid = l + r >> 1;
      |                       ~~^~~
In file included from /usr/include/c++/10/cassert:44,
                 from simurgh.cpp:5:
simurgh.cpp:285:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  285 |             assert(r < allEdges.size());
      |                    ~~^~~~~~~~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 9048 KB correct
2 Correct 2 ms 9052 KB correct
3 Correct 2 ms 9052 KB correct
4 Correct 3 ms 9052 KB correct
5 Correct 2 ms 9052 KB correct
6 Correct 1 ms 9072 KB correct
7 Correct 2 ms 9308 KB correct
8 Correct 1 ms 9052 KB correct
9 Correct 2 ms 9048 KB correct
10 Correct 2 ms 9052 KB correct
11 Correct 2 ms 9060 KB correct
12 Correct 2 ms 9052 KB correct
13 Correct 1 ms 9052 KB correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 9048 KB correct
2 Correct 2 ms 9052 KB correct
3 Correct 2 ms 9052 KB correct
4 Correct 3 ms 9052 KB correct
5 Correct 2 ms 9052 KB correct
6 Correct 1 ms 9072 KB correct
7 Correct 2 ms 9308 KB correct
8 Correct 1 ms 9052 KB correct
9 Correct 2 ms 9048 KB correct
10 Correct 2 ms 9052 KB correct
11 Correct 2 ms 9060 KB correct
12 Correct 2 ms 9052 KB correct
13 Correct 1 ms 9052 KB correct
14 Correct 14 ms 9304 KB correct
15 Correct 13 ms 9308 KB correct
16 Correct 13 ms 9480 KB correct
17 Correct 11 ms 9308 KB correct
18 Correct 5 ms 9276 KB correct
19 Correct 12 ms 9308 KB correct
20 Correct 13 ms 9492 KB correct
21 Correct 11 ms 9308 KB correct
22 Correct 6 ms 9052 KB correct
23 Correct 5 ms 9052 KB correct
24 Correct 6 ms 9276 KB correct
25 Correct 2 ms 9052 KB correct
26 Correct 5 ms 9052 KB correct
27 Correct 6 ms 9052 KB correct
28 Correct 3 ms 9052 KB correct
29 Correct 2 ms 9052 KB correct
30 Correct 8 ms 9332 KB correct
31 Correct 8 ms 9308 KB correct
32 Correct 8 ms 9328 KB correct
33 Correct 8 ms 9308 KB correct

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 9048 KB correct
2 Correct 2 ms 9052 KB correct
3 Correct 2 ms 9052 KB correct
4 Correct 3 ms 9052 KB correct
5 Correct 2 ms 9052 KB correct
6 Correct 1 ms 9072 KB correct
7 Correct 2 ms 9308 KB correct
8 Correct 1 ms 9052 KB correct
9 Correct 2 ms 9048 KB correct
10 Correct 2 ms 9052 KB correct
11 Correct 2 ms 9060 KB correct
12 Correct 2 ms 9052 KB correct
13 Correct 1 ms 9052 KB correct
14 Correct 14 ms 9304 KB correct
15 Correct 13 ms 9308 KB correct
16 Correct 13 ms 9480 KB correct
17 Correct 11 ms 9308 KB correct
18 Correct 5 ms 9276 KB correct
19 Correct 12 ms 9308 KB correct
20 Correct 13 ms 9492 KB correct
21 Correct 11 ms 9308 KB correct
22 Correct 6 ms 9052 KB correct
23 Correct 5 ms 9052 KB correct
24 Correct 6 ms 9276 KB correct
25 Correct 2 ms 9052 KB correct
26 Correct 5 ms 9052 KB correct
27 Correct 6 ms 9052 KB correct
28 Correct 3 ms 9052 KB correct
29 Correct 2 ms 9052 KB correct
30 Correct 8 ms 9332 KB correct
31 Correct 8 ms 9308 KB correct
32 Correct 8 ms 9328 KB correct
33 Correct 8 ms 9308 KB correct
34 Incorrect 116 ms 36436 KB WA in grader: NO
35 Halted 0 ms 0 KB -

Subtask #4
0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 9048 KB correct
2 Correct 2 ms 9052 KB correct
3 Incorrect 202 ms 134992 KB WA in grader: NO
4 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 9048 KB correct
2 Correct 2 ms 9052 KB correct
3 Correct 2 ms 9052 KB correct
4 Correct 3 ms 9052 KB correct
5 Correct 2 ms 9052 KB correct
6 Correct 1 ms 9072 KB correct
7 Correct 2 ms 9308 KB correct
8 Correct 1 ms 9052 KB correct
9 Correct 2 ms 9048 KB correct
10 Correct 2 ms 9052 KB correct
11 Correct 2 ms 9060 KB correct
12 Correct 2 ms 9052 KB correct
13 Correct 1 ms 9052 KB correct
14 Correct 14 ms 9304 KB correct
15 Correct 13 ms 9308 KB correct
16 Correct 13 ms 9480 KB correct
17 Correct 11 ms 9308 KB correct
18 Correct 5 ms 9276 KB correct
19 Correct 12 ms 9308 KB correct
20 Correct 13 ms 9492 KB correct
21 Correct 11 ms 9308 KB correct
22 Correct 6 ms 9052 KB correct
23 Correct 5 ms 9052 KB correct
24 Correct 6 ms 9276 KB correct
25 Correct 2 ms 9052 KB correct
26 Correct 5 ms 9052 KB correct
27 Correct 6 ms 9052 KB correct
28 Correct 3 ms 9052 KB correct
29 Correct 2 ms 9052 KB correct
30 Correct 8 ms 9332 KB correct
31 Correct 8 ms 9308 KB correct
32 Correct 8 ms 9328 KB correct
33 Correct 8 ms 9308 KB correct
34 Incorrect 116 ms 36436 KB WA in grader: NO
35 Halted 0 ms 0 KB -