Submission #105887

#	Time	Username	Problem	Language	Result	Execution time	Memory
105887		Kepperoni	Mergers (JOI19_mergers)	C++14	100 / 100	1345 ms	63452 KiB

mergers

#include <bits/stdc++.h>
#define x first
#define y second
#define pb push_back
#define all(x) x.begin(), x.end()

using namespace std;

typedef long long ll;
typedef pair<ll, ll> pii;

const int MAXN = 5e5 + 10;

int n, kk;
int gr[MAXN];
int le[MAXN], ri[MAXN];
int fi[MAXN], se[MAXN];
int cmi[MAXN], cma[MAXN], cnt[MAXN], tr[MAXN];
vector<int> k[MAXN];

int leaf = 1;
int ccnt = 1;
void prep(int v, int p = 0){
	le[v] = ccnt;
	ri[v] = ccnt;
	fi[gr[v]] = min(fi[gr[v]], ccnt);
	se[gr[v]] = max(se[gr[v]], ccnt);
	ccnt++;

	for(auto x : k[v]){
		if(x != p){
			prep(x, v);
			ri[v] = ri[x];
		}
	}
}

void go(int v, int p = 0){
	cmi[v] = fi[gr[v]];
	cma[v] = se[gr[v]];
	for(auto x : k[v]){
		if(x != p){
			go(x, v);				
			cmi[v] = min(cmi[v], cmi[x]);
			cma[v] = max(cma[v], cma[x]);
			cnt[v] += cnt[x];
		}
	}

	if(cmi[v] >= le[v] && cma[v] <= ri[v]){
		if(cnt[v] == 0 && v != 1)
			leaf++;
		if(cnt[v] == 1 && v == 1)
			leaf++;

		cnt[v] = 1;
	}
}

int main(){
	scanf(" %d %d", &n, &kk);
	
	for(int i=0; i<n-1; i++){
		int ca, cb; scanf(" %d %d", &ca, &cb);
		k[ca].pb(cb);
		k[cb].pb(ca);
	}

	for(int i=1; i<=n; i++) scanf(" %d", &gr[i]);
	for(int i=1; i<=kk; i++) fi[i] = 1e6;

	prep(1);
	go(1);

	printf("%d\n", leaf/2);
}

Compilation message (stderr)

mergers.cpp: In function 'int main()':
mergers.cpp:61:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf(" %d %d", &n, &kk);
  ~~~~~^~~~~~~~~~~~~~~~~~~
mergers.cpp:64:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int ca, cb; scanf(" %d %d", &ca, &cb);
               ~~~~~^~~~~~~~~~~~~~~~~~~~
mergers.cpp:69:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=1; i<=n; i++) scanf(" %d", &gr[i]);
                          ~~~~~^~~~~~~~~~~~~~~

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