Submission #623102

#	Time	Username	Problem	Language	Result	Execution time	Memory
623102		radal	Mergers (JOI19_mergers)	C++17	0 / 100	3075 ms	39424 KiB

mergers

#include <bits/stdc++.h>
#pragma GCC target("sse,sse2,avx2")
#pragma GCC optimize("unroll-loops,O2")
#define rep(i,l,r) for (int i = l; i < r; i++)
#define repr(i,r,l) for (int i = r; i >= l; i--)
#define X first
#define Y second
#define all(x) (x).begin() , (x).end()
#define pb push_back
#define endl '\n'
#define debug(x) cerr << #x << " : " << x << endl;
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pll;
constexpr int N = 5e5+10,mod = 998244353,inf = 1e9+10,sq = 700;
inline int mkay(int a,int b){
    if (a+b >= mod) return a+b-mod;
    if (a+b < 0) return a+b+mod;
    return a+b;
}
 
inline int poww(int a,int k){
    if (k < 0) return 0;
    int z = 1;
    while (k){
        if (k&1) z = 1ll*z*a%mod;
        a = 1ll*a*a%mod;
        k /= 2;
    } 
    return z; 
}
vector<int> adj[N],col[N];
int par[N][20],h[N],T,tin[N],calc[N];

void pre(int v,int p){
    par[v][0] = p;
    tin[v] = T++;
    for (int u : adj[v]){
        if (u == p) continue;
        h[u] = h[v]+1;
        pre(u,v);
    }
}
bool cmp(int u,int v){
    return (tin[u] < tin[v]);
}

int lca(int u,int v){
    if (h[u] < h[v]) swap(u,v);
    repr(i,19,0){
        if ((1 << i) <= h[u]-h[v]) u = par[u][i];
    }
    if (u == v) return u;
    repr(i,19,0){
        if (par[u][i] != par[v][i]){
            v = par[v][i];
            u = par[u][i];
        }
    }
    return par[v][0];
}
void dfs(int v,int p){
    for (int u : adj[v]){
        if (u != p){
            dfs(u,v);
            calc[v] += calc[u];
        }
    }
}
int main(){
    ios :: sync_with_stdio(0); cin.tie(0);
    mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
    int n,k;
    cin >> n >> k;
    rep(i,1,n){
        int u,v;
        cin >> u >> v;
        adj[u].pb(v);
        adj[v].pb(u);
    }
    rep(i,1,n+1){
        int c;
        cin >> c;
        col[c].pb(i);
    }
    rep(i,1,k+1)  sort(all(col[i]),cmp);
    pre(1,0);
    rep(j,1,20){
        rep(i,2,n+1)
            par[i][j] = par[par[i][j-1]][j-1];
    }
    rep(i,1,k+1){
        int sz = col[i].size();
        if (sz < 2) continue;
        rep(j,1,sz){
            calc[col[i][j]]++;
            calc[col[i][j-1]]++;
            calc[lca(col[i][j],col[i][j-1])] -= 2;
        }
    }
    dfs(1,0);
    int cnt = 0,ans = 0;
    rep(i,2,n+1) cnt += (calc[i] == 0);
    while (cnt){
        ans++;
        int mi = inf,x = -1,y = -1;
        rep(i,1,k){
            if (rng()%3 == 0) continue;
            if (col[i].empty()) continue;
            rep(j,i+1,k+1){
                if (col[j].empty()) continue;
                rep(f,1,n+1) calc[f] = 0;
                rep(f,1,k+1){
                    if (f == j || f == i) continue;
                    int sz = col[f].size();
                    if (sz < 2) continue;
                    rep(g,1,sz){
                        calc[col[f][g]]++;
                        calc[col[f][g-1]]++;
                        calc[lca(col[f][g],col[f][g-1])] -= 2;
                    }
                }
                vector<int> tmp;
                tmp.resize(col[i].size()+col[j].size());
                merge(all(col[i]),all(col[j]),tmp.begin(),cmp);
                int sz = tmp.size();
                rep(f,1,sz){
                    calc[tmp[f]]++;
                    calc[tmp[f-1]]++;
                    calc[lca(tmp[f],tmp[f-1])] -= 2;
                }
                dfs(1,0);
                int fuck = 0;
                rep(i,2,n+1) fuck += (calc[i] == 0);
                if (fuck < mi){
                    mi = fuck;
                    x = i;
                    y = j;
                }
            }
        }
        int i = x,j = y;
        rep(f,1,n+1) calc[f] = 0;
        rep(f,1,k+1){
            if (f == j || f == i) continue;
            int sz = col[f].size();
            if (sz < 2) continue;
            rep(g,1,sz){
                calc[col[f][g]]++;
                calc[col[f][g-1]]++;
                calc[lca(col[f][g],col[f][g-1])] -= 2;
            }
        }
        vector<int> tmp;
        tmp.resize(col[i].size()+col[j].size());
        merge(all(col[i]),all(col[j]),tmp.begin(),cmp);
        int sz = tmp.size();
        rep(f,1,sz){
            calc[tmp[f]]++;
            calc[tmp[f-1]]++;
            calc[lca(tmp[f],tmp[f-1])] -= 2;
        }
        col[i] = tmp;
        col[j].clear();
        dfs(1,0);
        cnt = 0;
        rep(i,2,n+1) cnt += (calc[i] == 0);
    }
    cout << ans;
}

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