Submission #441267

#	Time	Username	Problem	Language	Result	Execution time	Memory
441267		cheetose	Meetings 2 (JOI21_meetings2)	C++17	100 / 100	469 ms	49568 KiB

meetings2

#include <bits/stdc++.h>
#define mp make_pair
#define pb push_back
#define X first
#define Y second
#define y0 y12
#define y1 y22
#define INF 1987654321
#define PI 3.141592653589793238462643383279502884
#define fup(i,a,b,c) for(int (i)=(a);(i)<=(b);(i)+=(c))
#define fdn(i,a,b,c) for(int (i)=(a);(i)>=(b);(i)-=(c))
#define MEM0(a) memset((a),0,sizeof(a))
#define MEM_1(a) memset((a),-1,sizeof(a))
#define ALL(a) a.begin(),a.end()
#define COMPRESS(a) sort(ALL(a));a.resize(unique(ALL(a))-a.begin())
#define SYNC ios_base::sync_with_stdio(false);cin.tie(0)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef double db;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef pair<int, int> Pi;
typedef pair<ll, ll> Pll;
typedef pair<db, db> Pd;
typedef vector<int> Vi;
typedef vector<ll> Vll;
typedef vector<ld> Vd;
typedef vector<Pi> VPi;
typedef vector<Pll> VPll;
typedef vector<Pd> VPd;
typedef tuple<int, int, int> iii;
typedef tuple<int, int, int, int> iiii;
typedef tuple<ll, ll, ll> LLL;
typedef vector<iii> Viii;
typedef vector<LLL> VLLL;
typedef complex<double> base;
const int MOD = 1000000007;
ll POW(ll a, ll b, ll MMM = MOD) { ll ret = 1; for (; b; b >>= 1, a = (a*a) % MMM)if (b & 1)ret = (ret*a) % MMM; return ret; }
int dx[] = { 0,1,0,-1,1,1,-1,-1 }, dy[] = { 1,0,-1,0,1,-1,1,-1 };
int ddx[] = { -1,-2,1,-2,2,-1,2,1 }, ddy[] = { -2,-1,-2,1,-1,2,1,2 };

Vi v[200001];
VPi vv[200001];
int depth[200001],parent[200001][18];
int cnt[200001];
void dfs(int N,int p=-1){
	parent[N][0]=p;
	cnt[N]=1;
	for(int next:v[N]){
		if(next==p)continue;
		depth[next]=depth[N]+1;
		dfs(next,N);
		cnt[N]+=cnt[next];
	}
}
int LCA(int x, int y) {
	if (depth[x] < depth[y])swap(x, y);
	int dif = depth[x] - depth[y];
	for (int j = 0; dif > 0; j++) {
		if (dif & 1)x = parent[x][j];
		dif >>= 1;
	}

	if (x != y) {
		fdn(j,16,0,1) {
			if (parent[x][j] != -1 && parent[x][j] != parent[y][j]) {
				x = parent[x][j];
				y = parent[y][j];
			}
		}
		x = parent[x][0];
	}
	return x;
}
int dist(int x,int y){
	int u=LCA(x,y);
	return depth[x]+depth[y]-2*depth[u];
}
int cc,n;
void dfs2(int N,int p=-1){
	for(int next:v[N]){
		if(next==p)continue;
		vv[min(cnt[next],n-cnt[next])].pb(mp(N,next));
		dfs2(next,N);
	}
}
int ans[200001];
bool chk[200001];
int upd(int x,int &sz,int &a,int &b){
	chk[x]=1;
	sz++;
	if(sz==1){
		a=x;
		return 1;
	}else if(sz==2){
		b=x;
		return 2;
	}else{
		int d1=dist(a,b),d2=dist(a,x),d3=dist(b,x);
		int res=max({d1,d2,d3});
		if(d2==res)b=x;
		else if(d3==res)a=x;
		return res+1;
	}
}
int main(){
	MEM_1(parent);
	scanf("%d",&n);
	fup(i,1,n-1,1){
		int x,y;
		scanf("%d%d",&x,&y);
		v[x].pb(y);
		v[y].pb(x);
	}
	dfs(1);
	fup(j,0,16,1)
		fup(i,1,n,1)
		if (parent[i][j] != -1)
			parent[i][j + 1] = parent[parent[i][j]][j];
	dfs2(1);
	int sz=0,r=1;
	int a=-1,b=-1;
	fdn(i,n,1,1){
		if(i&1)ans[i]=1;
		else{
			for(Pi P:vv[i/2]){
				if(!chk[P.X])r=upd(P.X,sz,a,b);
				if(!chk[P.Y])r=upd(P.Y,sz,a,b);
			}
			ans[i]=r;
		}
	}
	fup(i,1,n,1)printf("%d\n",ans[i]);
}

Compilation message (stderr)

meetings2.cpp: In function 'int LCA(int, int)':
meetings2.cpp:11:30: warning: unnecessary parentheses in declaration of 'j' [-Wparentheses]
   11 | #define fdn(i,a,b,c) for(int (i)=(a);(i)>=(b);(i)-=(c))
      |                              ^
meetings2.cpp:66:3: note: in expansion of macro 'fdn'
   66 |   fdn(j,16,0,1) {
      |   ^~~
meetings2.cpp: In function 'int main()':
meetings2.cpp:10:30: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   10 | #define fup(i,a,b,c) for(int (i)=(a);(i)<=(b);(i)+=(c))
      |                              ^
meetings2.cpp:110:2: note: in expansion of macro 'fup'
  110 |  fup(i,1,n-1,1){
      |  ^~~
meetings2.cpp:10:30: warning: unnecessary parentheses in declaration of 'j' [-Wparentheses]
   10 | #define fup(i,a,b,c) for(int (i)=(a);(i)<=(b);(i)+=(c))
      |                              ^
meetings2.cpp:117:2: note: in expansion of macro 'fup'
  117 |  fup(j,0,16,1)
      |  ^~~
meetings2.cpp:10:30: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   10 | #define fup(i,a,b,c) for(int (i)=(a);(i)<=(b);(i)+=(c))
      |                              ^
meetings2.cpp:118:3: note: in expansion of macro 'fup'
  118 |   fup(i,1,n,1)
      |   ^~~
meetings2.cpp:11:30: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   11 | #define fdn(i,a,b,c) for(int (i)=(a);(i)>=(b);(i)-=(c))
      |                              ^
meetings2.cpp:124:2: note: in expansion of macro 'fdn'
  124 |  fdn(i,n,1,1){
      |  ^~~
meetings2.cpp:10:30: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   10 | #define fup(i,a,b,c) for(int (i)=(a);(i)<=(b);(i)+=(c))
      |                              ^
meetings2.cpp:134:2: note: in expansion of macro 'fup'
  134 |  fup(i,1,n,1)printf("%d\n",ans[i]);
      |  ^~~
meetings2.cpp:109:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  109 |  scanf("%d",&n);
      |  ~~~~~^~~~~~~~~
meetings2.cpp:112:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  112 |   scanf("%d%d",&x,&y);
      |   ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 16 / 16
• Subtask 3: 80 / 80