Submission #925020

#	Time	Username	Problem	Language	Result	Execution time	Memory
925020		Andrey	Capital City (JOI20_capital_city)	C++14	100 / 100	437 ms	43096 KiB

capital_city

#include <bits/stdc++.h>
using namespace std;

vector<int> haha[200001];
vector<int> bruh[200001];
vector<int> col(200001);
vector<int> par(200001,-1);
vector<int> st(200001);
vector<int> wut(0);
vector<bool> yay(200001,1);
vector<bool> no(200001,1);
vector<bool> banana(200001,true);

void dfs(int a, int t, int t2) {
    par[a] = t;
    st[a] = 1;
    wut.push_back(a);
    for(int v: haha[a]) {
        if(v != t && banana[v]) {
            dfs(v,a,t2);
            st[a]+=st[v];
        }
    }
}

int dude(int a, int t) {
   // cout << a << endl;
    int ans = INT_MAX;
    int c = a;
    dfs(a,0,t);
    bool yeah = false;
    while(!yeah) {
        yeah = true;
        for(int v: haha[c]) {
            if(banana[v] && st[v]*2 >= st[a] && st[v] < st[c]) {
                yeah = false;
                c = v;
                break;
            }
        }
    }
  //  cout << a << " " << c << endl;
    wut.clear();
    dfs(c,0,t);
    int br = -1,x = 0;
    vector<int> wow(1,col[c]);
    for(int i = 0; i < wow.size() && x == 0; i++) {
        if(yay[wow[i]]) {
            yay[wow[i]] = false;
            br++;
            for(int v: bruh[wow[i]]) {
                if(par[v] == -1) {
                    x = 1;
                    break;
                }
                while(v != 0 && no[v]) {
                    no[v] = false;
                    wow.push_back(col[v]);
                    v = par[v];
                }
            }
        }
    }
    if(x == 0) {
        ans = min(ans,br);
    }
    for(int i = 0; i < wut.size(); i++) {
        no[wut[i]]= true;
        par[wut[i]] = -1;
    }
    for(int i = 0; i < wow.size(); i++) {
        yay[wow[i]] = true;
    }
    banana[c] = false;
    for(int v: haha[c]) {
        if(banana[v]) {
            ans = min(ans,dude(v,c));
        }
    }
    return ans;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int n,k,a,b;
    cin >> n >> k;
    for(int i = 0; i < n-1; i++) {
        cin >> a >> b;
        haha[a].push_back(b);
        haha[b].push_back(a);
    }
    for(int i = 1; i <= n; i++) {
        cin >> col[i];
        bruh[col[i]].push_back(i);
    }
    cout << dude(1,-1);
    return 0;
}

Compilation message (stderr)

capital_city.cpp: In function 'int dude(int, int)':
capital_city.cpp:47:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |     for(int i = 0; i < wow.size() && x == 0; i++) {
      |                    ~~^~~~~~~~~~~~
capital_city.cpp:67:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   67 |     for(int i = 0; i < wut.size(); i++) {
      |                    ~~^~~~~~~~~~~~
capital_city.cpp:71:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   71 |     for(int i = 0; i < wow.size(); i++) {
      |                    ~~^~~~~~~~~~~~

• Subtask 1: 1 / 1
• Subtask 2: 10 / 10
• Subtask 3: 30 / 30
• Subtask 4: 59 / 59