Submission #442411

#	Time	Username	Problem	Language	Result	Execution time	Memory
442411		koioi.org-koosaga	Counterspells (CPSPC17_counterspells)	C++17	60 / 100	1084 ms	16636 KiB

Main

#include <bits/stdc++.h>
#define sz(v) ((int)(v).size())
#define all(v) (v).begin(), (v).end()
using namespace std;
using lint = long long;
using pi = pair<int, int>;
const int MAXN = 200005;
const int mod = 1e9 + 7;
 
int n, p[MAXN], dep[MAXN], cnt[MAXN];
vector<int> gph[MAXN];

int sz[MAXN];
int din[MAXN], dout[MAXN], chn[MAXN], piv;

void hld(int x){
	din[x] = ++piv;
	if(sz(gph[x])){
		chn[gph[x][0]] = chn[x];
		hld(gph[x][0]);
		for(int i = 1; i < sz(gph[x]); i++){
			chn[gph[x][i]] = gph[x][i];
			hld(gph[x][i]);
		}
	}
	dout[x] = piv;
}

pi forward(int x){
	int ret = 0;
	while(~p[x] && cnt[x] == cnt[p[x]]){
		x = p[x];
		ret++;
	}
	return pi(x, ret);
}

void add_until(int s, int e, int x){
	while(s != e){
		cnt[s] += x;	
		s = p[s];
	}
	if(~s) cnt[s] += x;
}

int main(){
	scanf("%d",&n);
	p[0] = -1;
	for(int i = 1; i <= n; i++){
		scanf("%d",&p[i]);
		dep[i] = dep[p[i]] + 1;
		if(dep[i] % 2) cnt[i]++;
		gph[p[i]].push_back(i);
	}
	for(int i = n; i; i--){
		sz[i]++;
		if(~p[i]) sz[p[i]] += sz[i];
		sort(all(gph[i]), [&](const int &a, const int &b){
			return sz[a] > sz[b];
		});
	}
	hld(0);
	for(int i = 1; i <= n; i++){
		int ans = 0;
		if(dep[i] % 2){
			int j = i;
			if(cnt[p[j]] == 0){
				tie(j, ans) = forward(p[j]);
				ans++;
			}
			add_until(p[i], p[j], 1);
		}
		else{
			int j = i;
			if(cnt[p[j]] == 1){
				tie(j, ans) = forward(p[j]);
				ans++;
			}
			add_until(p[i], p[j], -1);
		}
		printf("%d\n", ans);
	}
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:47:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |  scanf("%d",&n);
      |  ~~~~~^~~~~~~~~
Main.cpp:50:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |   scanf("%d",&p[i]);
      |   ~~~~~^~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 0 / 20
• Subtask 4: 20 / 20
• Subtask 5: 0 / 20