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답안 #205099

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
205099 2020-02-27T23:58:30 Z achibasadzishvili Mergers (JOI19_mergers) C++17
0 / 100
 159 ms 81496 KB 
#include<bits/stdc++.h>
#define ll int
#define f first
#define s second
#define pb push_back
using namespace std;
ll P[500002][20],lvl[500002],pp[500002],in[500002],out[500002],timer,ch[500002];
ll n,k,bst[500002],c[500002],par[500002],p[500002],sz[500002],raod[500002];
ll fix[500002];
set<ll>st[500002];
vector<ll>v[500002],del[500002],fer[500002];
void dfs(ll x,ll par) {
    P[x][0]=par;
    pp[x] = par;
    for (int i=1;i<=19;i++)
        P[x][i]=P[P[x][i-1]][i-1];
    timer++;
    in[x]=timer;
    ch[x] = 1;
    for (int i=0;i<v[x].size();i++)
        if (v[x][i] != par) {
            lvl[v[x][i]]=lvl[x]+1;
            dfs(v[x][i],x);
            ch[x] += ch[v[x][i]];
        }
    out[x]=timer;
}

ll lca(ll a,ll b) {
    if(lvl[a] > lvl[b])swap(a,b);
    if (in[a] <= in[b] && out[b] <= out[a]) return a;
    for (int i=19;i>=0;i--)
        if (P[a][i])
            if (!(in[P[a][i]] <= in[b] && out[b] <= out[P[a][i]]))
                a=P[a][i];
    return P[a][0];
}
ll find(ll x){
    if(p[x] == x)return x;
    return p[x] = find(p[x]);
}
void join(ll x,ll y){
    //cout << x << " " << y << endl;
    x = find(x);
    y = find(y);
    if(x == y)return;
    if(sz[y] > sz[x])swap(x , y);
    sz[x] += sz[y];
    p[y] = x;
}
void solve(ll x){
    if(v[x].size() == 0){
        bst[x] = x;
        if(par[c[x]] != x)st[x].insert(c[x]);
        return;
    }
    for(int i=0; i<v[x].size(); i++)
        solve(v[x][i]);
    bst[x] = bst[v[x][0]];
    if(st[bst[x]].size() > 0){
        join(c[x] , (*st[bst[x]].begin()));
    }
    st[bst[x]].insert(c[x]);
    for(int i=1; i<v[x].size(); i++){
        ll t = bst[v[x][i]];
        for(set<ll>::iterator it = st[t].begin(); it != st[t].end(); it++){
            join(c[x] , (*it));
            st[bst[x]].insert((*it));
        }
    }
    for(int i=0; i<del[x].size(); i++)
        st[bst[x]].erase(st[bst[x]].find(del[x][i]));
}
int main(){
    ios::sync_with_stdio(false);
    cin >> n >> 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];
        fer[c[i]].pb(i);
    }
    
    dfs(1 , 0);
    
    for(int i=1; i<=k; i++){
        par[i] = fer[i][0];
        for(int j=1; j<fer[i].size(); j++)
            par[i] = lca(par[i] , fer[i][j]);
        del[par[i]].pb(i);
    }
    
    for(int i=1; i<=n; i++){
        sz[i] = 1;
        p[i] = i;
        v[i].clear();
    }
    
    for(int i=2; i<=n; i++)
        v[pp[i]].pb(i);
    
    for(int i=1; i<=n; i++)
        for(int j=1; j<v[i].size(); j++)
            if(ch[v[i][j]] > ch[v[i][0]])
                swap(v[i][j] , v[i][0]);
    
    
    solve(1);
    
    for(int i=1; i<=n; i++){
        for(int j=0; j<v[i].size(); j++){
            ll x = v[i][j];
            if(find(c[i]) != find(c[x])){
                raod[c[i]]++;
                raod[c[x]]++;
            }
        }
    }
    ll ans = 1;
    for(int i=1; i<=k; i++){
        if(!fix[find(i)]){
            fix[find(i)] = 1;
            if(raod[find(i)] == 1)ans++;
        }
    }
    
    cout << ans / 2 << '\n';
    
    
    return 0;
}

Compilation message

mergers.cpp: In function 'void dfs(int, int)':
mergers.cpp:20:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i=0;i<v[x].size();i++)
                  ~^~~~~~~~~~~~
mergers.cpp: In function 'void solve(int)':
mergers.cpp:57:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<v[x].size(); i++)
                  ~^~~~~~~~~~~~
mergers.cpp:64:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=1; i<v[x].size(); i++){
                  ~^~~~~~~~~~~~
mergers.cpp:71:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<del[x].size(); i++)
                  ~^~~~~~~~~~~~~~
mergers.cpp: In function 'int main()':
mergers.cpp:94:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=1; j<fer[i].size(); j++)
                      ~^~~~~~~~~~~~~~
mergers.cpp:109:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=1; j<v[i].size(); j++)
                      ~^~~~~~~~~~~~
mergers.cpp:117:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=0; j<v[i].size(); j++){
                      ~^~~~~~~~~~~~

Subtask #1
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 43 ms 59128 KB Output is correct
2 Correct 45 ms 59128 KB Output is correct
3 Correct 42 ms 59128 KB Output is correct
4 Correct 42 ms 59128 KB Output is correct
5 Correct 45 ms 59128 KB Output is correct
6 Correct 44 ms 59128 KB Output is correct
7 Correct 42 ms 59128 KB Output is correct
8 Correct 42 ms 59128 KB Output is correct
9 Correct 43 ms 59128 KB Output is correct
10 Correct 42 ms 59128 KB Output is correct
11 Correct 42 ms 59256 KB Output is correct
12 Correct 44 ms 59128 KB Output is correct
13 Incorrect 43 ms 59128 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #2
0 / 24.0

# 결과 실행 시간 메모리 Grader output
1 Correct 43 ms 59128 KB Output is correct
2 Correct 45 ms 59128 KB Output is correct
3 Correct 42 ms 59128 KB Output is correct
4 Correct 42 ms 59128 KB Output is correct
5 Correct 45 ms 59128 KB Output is correct
6 Correct 44 ms 59128 KB Output is correct
7 Correct 42 ms 59128 KB Output is correct
8 Correct 42 ms 59128 KB Output is correct
9 Correct 43 ms 59128 KB Output is correct
10 Correct 42 ms 59128 KB Output is correct
11 Correct 42 ms 59256 KB Output is correct
12 Correct 44 ms 59128 KB Output is correct
13 Incorrect 43 ms 59128 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #3
0 / 14.0

# 결과 실행 시간 메모리 Grader output
1 Correct 43 ms 59128 KB Output is correct
2 Correct 45 ms 59128 KB Output is correct
3 Correct 42 ms 59128 KB Output is correct
4 Correct 42 ms 59128 KB Output is correct
5 Correct 45 ms 59128 KB Output is correct
6 Correct 44 ms 59128 KB Output is correct
7 Correct 42 ms 59128 KB Output is correct
8 Correct 42 ms 59128 KB Output is correct
9 Correct 43 ms 59128 KB Output is correct
10 Correct 42 ms 59128 KB Output is correct
11 Correct 42 ms 59256 KB Output is correct
12 Correct 44 ms 59128 KB Output is correct
13 Incorrect 43 ms 59128 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #4
0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 138 ms 79192 KB Output is correct
2 Correct 159 ms 81496 KB Output is correct
3 Incorrect 44 ms 59768 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 43 ms 59128 KB Output is correct
2 Correct 45 ms 59128 KB Output is correct
3 Correct 42 ms 59128 KB Output is correct
4 Correct 42 ms 59128 KB Output is correct
5 Correct 45 ms 59128 KB Output is correct
6 Correct 44 ms 59128 KB Output is correct
7 Correct 42 ms 59128 KB Output is correct
8 Correct 42 ms 59128 KB Output is correct
9 Correct 43 ms 59128 KB Output is correct
10 Correct 42 ms 59128 KB Output is correct
11 Correct 42 ms 59256 KB Output is correct
12 Correct 44 ms 59128 KB Output is correct
13 Incorrect 43 ms 59128 KB Output isn't correct
14 Halted 0 ms 0 KB -