CF1009F Dominant Indices [长链剖分]

Posted 2020-11-28 isaunoya

长链剖分板子题QAQ

// powered by c++11
// by Isaunoya
#include <bits/stdc++.h>
#define rep(i, x, y) for (register int i = (x); i <= (y); ++i)
#define Rep(i, x, y) for (register int i = (x); i >= (y); --i)
using namespace std;
using db = double;
using ll = long long;
using uint = unsigned int;
#define Tp template
using pii = pair<int, int>;
#define fir first
#define sec second
Tp<class T> void cmax(T& x, const T& y) {if (x < y) x = y;} Tp<class T> void cmin(T& x, const T& y) {if (x > y) x = y;}
#define all(v) v.begin(), v.end()
#define sz(v) ((int)v.size())
#define pb emplace_back
Tp<class T> void sort(vector<T>& v) { sort(all(v)); } Tp<class T> void reverse(vector<T>& v) { reverse(all(v)); }
Tp<class T> void unique(vector<T>& v) { sort(all(v)), v.erase(unique(all(v)), v.end()); }
const int SZ = 1 << 23 | 233;
struct FILEIN { char qwq[SZ], *S = qwq, *T = qwq, ch;
#ifdef __WIN64
#define GETC getchar
#else
  char GETC() { return (S == T) && (T = (S = qwq) + fread(qwq, 1, SZ, stdin), S == T) ? EOF : *S++; }
#endif
  FILEIN& operator>>(char& c) {while (isspace(c = GETC()));return *this;}
  FILEIN& operator>>(string& s) {while (isspace(ch = GETC())); s = ch;while (!isspace(ch = GETC())) s += ch;return *this;}
  Tp<class T> void read(T& x) { bool sign = 0;while ((ch = GETC()) < 48) sign ^= (ch == 45); x = (ch ^ 48);
    while ((ch = GETC()) > 47) x = (x << 1) + (x << 3) + (ch ^ 48); x = sign ? -x : x;
  }FILEIN& operator>>(int& x) { return read(x), *this; } FILEIN& operator>>(ll& x) { return read(x), *this; }
} in;
struct FILEOUT {const static int LIMIT = 1 << 22 ;char quq[SZ], ST[233];int sz, O;
  ~FILEOUT() { flush() ; }void flush() {fwrite(quq, 1, O, stdout); fflush(stdout);O = 0;}
  FILEOUT& operator<<(char c) {return quq[O++] = c, *this;}
  FILEOUT& operator<<(string str) {if (O > LIMIT) flush();for (char c : str) quq[O++] = c;return *this;}
  Tp<class T> void write(T x) {if (O > LIMIT) flush();if (x < 0) {quq[O++] = 45;x = -x;}
        do {ST[++sz] = x % 10 ^ 48;x /= 10;} while (x);while (sz) quq[O++] = ST[sz--];
  }FILEOUT& operator<<(int x) { return write(x), *this; } FILEOUT& operator<<(ll x) { return write(x), *this; }
} out;
#define int long long

int n ;
const int maxn = 1e6 + 61 ;
vector < int > g[maxn] ;
int ans[maxn] , son[maxn] , len[maxn] ;
void dfs(int u , int fa) {
    for(int v : g[u]) {
        if(v == fa) continue ;
        dfs(v , u) ;
        if(len[v] > len[son[u]])
            son[u] = v ;
    }
    len[u] = len[son[u]] + 1 ;
}
int dfn[maxn] , idx = 0 ;
void dfsdfn(int u , int fa) {
    dfn[u] = ++ idx ;
    if(son[u]) dfsdfn(son[u] , u) ;
    for(int v : g[u]) 
        if(v != fa && v != son[u])
            dfsdfn(v , u) ;
}

int cnt[maxn] ;
void dp(int u , int fa) {
    if(son[u]) {
        dp(son[u] , u) ;
        ans[u] = ans[son[u]] + 1 ;
    }
    for(int v : g[u]) {
        if(v != fa && v != son[u]) {
            dp(v , u) ;
            for(int j = 1 ; j <= len[v] ; j ++) {
                cnt[dfn[u] + j] += cnt[dfn[v] + j - 1] ;
                if(cnt[dfn[u] + ans[u]] < cnt[dfn[u] + j]) ans[u] = j ;
                if(cnt[dfn[u] + ans[u]] == cnt[dfn[u] + j] && ans[u] > j) 
                    ans[u] = j ;
            }
        }
    }
    cnt[dfn[u]] = 1 ;
    if(cnt[dfn[u] + ans[u]] < cnt[dfn[u]]) ans[u] = 0 ;
    if(cnt[dfn[u] + ans[u]] == cnt[dfn[u]] && ans[u] > 0)
        ans[u] = 0 ;
}

signed main() {
  // code begin.
    in >> n ;
    rep(i , 2 , n) {
        int u , v ;
        in >> u >> v , g[u].pb(v) , g[v].pb(u) ;
    }
    dfs(1 , 0) ;
    dfsdfn(1 , 0) ;
    dp(1 , 0) ;
    rep(i , 1 , n) 
        out << ans[i] << '
' ;
    return 0;
  // code end.
}