Submission #218072

#	Time	Username	Problem	Language	Result	Execution time	Memory
218072		achibasadzishvili	Capital City (JOI20_capital_city)	C++14	100 / 100	1039 ms	39704 KiB

capital_city

#include<bits/stdc++.h>
#define ll long long
#define f first
#define s second
#define pb push_back
#define N 200005
using namespace std;
ll ans,ch[N],p[N],siz,center,fi[N],fix[N],ra[N],raod[N],c[N],n,k;
vector<ll>ver,v[N],fer[N];
queue<ll>q;
void calc(ll x,ll par){
    ch[x] = 1;
    siz++;
    for(int i=0; i<v[x].size(); i++)
        if(v[x][i] != par && !fix[v[x][i]]){
            calc(v[x][i] , x);
            ch[x] += ch[v[x][i]];
        }
}
void findcenter(ll x,ll par){
    if(center)return;
    for(int i=0; i<v[x].size(); i++)
        if(!fix[v[x][i]] && v[x][i] != par && ch[v[x][i]] >= (siz / 2))
            findcenter(v[x][i] , x);
    if(!center)center = x;
}
void go(ll x,ll par){
    ra[c[x]]++;
    fer[c[x]].pb(x);
    p[x] = par;
    ver.pb(x);
    for(int i=0; i<v[x].size(); i++)
        if(v[x][i] != par && !fix[v[x][i]])
            go(v[x][i] , x);
}
void solve(ll x){
    siz = 0;
    calc(x , 0);
    center = 0;
    findcenter(x , 0);
    x = center;
    ver.clear();
    go(x , 0);
    while(q.size())q.pop();
    for(int i=0; i<ver.size(); i++){
        if(c[ver[i]] == c[x]){
            fi[ver[i]] = 1;
            q.push(ver[i]);
        }
    }
    bool yep = true;
    ll val = 0;
    while(q.size()){
        int t = q.front();
        q.pop();
        if(ra[c[t]] != raod[c[t]]){
            yep = false;
            break;
        }
        if(fi[p[t]] == 0 && p[t] != 0){
            val++;
            for(int i=0; i<fer[c[p[t]]].size(); i++){
                int cur = fer[c[p[t]]][i];
                fi[cur] = 1;
                q.push(cur);
            }
        }
    }
    if(yep){
        ans = min(ans , val);
    }
    for(int i=0; i<ver.size(); i++){
        ra[c[ver[i]]] = 0;
        fer[c[ver[i]]].clear();
        fi[ver[i]] = 0;
    }
    fix[x] = 1;
    for(int i=0; i<v[x].size(); i++)
        if(!fix[v[x][i]])
            solve(v[x][i]);
}
int main(){
    ios::sync_with_stdio(false);
    cin >> n >> k;
    ans = k;
    for(int i=1; i<n; i++){
        ll x,y;
        cin >> x >> y;
        v[x].pb(y);
        v[y].pb(x);
    }
    
    for(int i=1; i<=n; i++){
        cin >> c[i];
        raod[c[i]]++;
    }
    
    solve(1);
    
    cout << ans << '\n';
    
    return 0;
}

Compilation message (stderr)

capital_city.cpp: In function 'void calc(long long int, long long int)':
capital_city.cpp:14:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<v[x].size(); i++)
                  ~^~~~~~~~~~~~
capital_city.cpp: In function 'void findcenter(long long int, long long int)':
capital_city.cpp:22:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<v[x].size(); i++)
                  ~^~~~~~~~~~~~
capital_city.cpp: In function 'void go(long long int, long long int)':
capital_city.cpp:32:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<v[x].size(); i++)
                  ~^~~~~~~~~~~~
capital_city.cpp: In function 'void solve(long long int)':
capital_city.cpp:45:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<ver.size(); i++){
                  ~^~~~~~~~~~~
capital_city.cpp:62:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for(int i=0; i<fer[c[p[t]]].size(); i++){
                          ~^~~~~~~~~~~~~~~~~~~~
capital_city.cpp:72:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<ver.size(); i++){
                  ~^~~~~~~~~~~
capital_city.cpp:78:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<v[x].size(); i++)
                  ~^~~~~~~~~~~~

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