제출 #923917

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
923917		boris_mihov	Mergers (JOI19_mergers)	C++17	0 / 100	37 ms	26320 KiB

mergers

#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>
#include <bitset>
#include <random>
#include <queue>
#include <set>

typedef long long llong;
const int MAXN = 500000 + 10;
const int INTINF = 2e9;
const llong INF = 1e18;
const int MAXLOG = 17;

int n, k;
int s[MAXN];
int sz[MAXN];
int cnt[MAXN];
int full[MAXN];
int szBad[MAXN];
bool isBad[MAXN];
std::vector <int> g[MAXN];

void buildDFS(int node, int par)
{
    for (int &u : g[node])
    {
        if (u == par)
        {
            std::swap(u, g[node].back());
            g[node].pop_back();
            break;
        }
    }

    sz[node] = 1;
    for (const int &u : g[node])
    {
        if (u == par)
        {
            continue;
        }

        buildDFS(u, node);
        sz[node] += sz[u];
    }

    for (int i = 1 ; i < g[node].size() ; ++i)
    {
        if (sz[g[node][i]] > sz[g[node][0]])
        {
            std::swap(g[node][i], g[node][0]);
        }
    }
}

int cntUnfull;
void addNode(int node)
{
    cntUnfull -= (0 < cnt[s[node]] && cnt[s[node]] < full[s[node]]);
    cnt[s[node]]++;
    cntUnfull += (0 < cnt[s[node]] && cnt[s[node]] < full[s[node]]);
}

void remNode(int node)
{
    cntUnfull -= (0 < cnt[s[node]] && cnt[s[node]] < full[s[node]]);
    cnt[s[node]]--;
    cntUnfull += (0 < cnt[s[node]] && cnt[s[node]] < full[s[node]]);
}

void addDFS(int node)
{
    addNode(node);
    for (const int &u : g[node])
    {
        addDFS(u);
    }
}

void remDFS(int node)
{
    remNode(node);
    for (const int &u : g[node])
    {
        addDFS(u);
    }
}

void solveDFS(int node)
{
    for (int i = 1 ; i < g[node].size() ; ++i)
    {
        solveDFS(g[node][i]);
        remDFS(g[node][i]);
    }

    if (g[node].size())
    {
        solveDFS(g[node][0]);
    }

    for (int i = 1 ; i < g[node].size() ; ++i)
    {
        addDFS(g[node][i]);
    }

    addNode(node);
    if (cntUnfull == 0)
    {
        isBad[node] = true;
    }
}

int ans;
void calcDFS(int node)
{
    szBad[node] = isBad[node];
    for (const int &u : g[node])
    {
        calcDFS(u);
        szBad[node] += szBad[u];
    }
}

void ansDFS(int node)
{
    for (const int &u : g[node])
    {
        if (szBad[u] > szBad[1] / 2)
        {
            ans += isBad[node];
            ansDFS(u);
            return;
        }
    }

    ans += szBad[node] / 2;
    ans += szBad[node] % 2;
}

void solve()
{
    buildDFS(1, 0);
    solveDFS(1);
    isBad[1] = false;
    calcDFS(1);
    ansDFS(1);
    
    // for (int i = 2 ; i <= n ; ++i)
    // {
    //     std::cout << isBad[i] << '\n';
    // }   

    std::cout << ans << '\n';
}

void input()
{
    std::cin >> n >> k;
    for (int i = 1 ; i < n ; ++i)
    {
        int u, v;
        std::cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }

    for (int i = 1 ; i <= n ; ++i)
    {
        std::cin >> s[i];
        full[s[i]]++;
    }
}

void fastIOI()
{   
    std::ios_base :: sync_with_stdio(0);
    std::cout.tie(nullptr);
    std::cin.tie(nullptr);
}

int main()
{
    fastIOI();
    input();
    solve();

    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

mergers.cpp: In function 'void buildDFS(int, int)':
mergers.cpp:50:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |     for (int i = 1 ; i < g[node].size() ; ++i)
      |                      ~~^~~~~~~~~~~~~~~~
mergers.cpp: In function 'void solveDFS(int)':
mergers.cpp:94:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   94 |     for (int i = 1 ; i < g[node].size() ; ++i)
      |                      ~~^~~~~~~~~~~~~~~~
mergers.cpp:105:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  105 |     for (int i = 1 ; i < g[node].size() ; ++i)
      |                      ~~^~~~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 24
• Subtask 3: 0 / 14
• Subtask 4: 0 / 22
• Subtask 5: 0 / 30