Submission #728128

#	Time	Username	Problem	Language	Result	Execution time	Memory
728128		josanneo22	Fireworks (APIO16_fireworks)	C++17	100 / 100	479 ms	29868 KiB

fireworks

#include<bits/stdc++.h>
#define MAXN 300010
#define int long long
using namespace std;
int n,m,ans;
int fa[MAXN],w[MAXN],deg[MAXN];
int val[MAXN<<1],d[MAXN<<1],rt[MAXN],tot;
int lc[MAXN<<1],rc[MAXN<<1];
int create(int v){
	val[++tot]=v;d[tot]=0;
	return tot;
}
int merge(int p,int q){
	if(!p||!q)return p+q;
	if(val[p]<val[q])swap(p,q);
	rc[p]=merge(rc[p],q);
	if(d[lc[p]]<d[rc[p]])swap(lc[p],rc[p]);
	d[p]=d[rc[p]]+1;return p;
}
void pop(int &p){p=merge(lc[p],rc[p]);}
signed main(){
	scanf("%lld%lld",&n,&m);
	for(int i=2;i<=n+m;i++){
		scanf("%lld%lld",&fa[i],&w[i]);
		ans+=w[i];deg[fa[i]]++;
	}
	for(int u=n+m;u>=2;u--){
		if(u<=n)while(deg[u]-->1)pop(rt[u]);
		int R=val[rt[u]];pop(rt[u]);
		int L=val[rt[u]];pop(rt[u]);
		rt[u]=merge(rt[u],merge(create(L+w[u]),create(R+w[u])));
		rt[fa[u]]=merge(rt[fa[u]],rt[u]);
	}
	while(deg[1]--)pop(rt[1]);
	while(rt[1])ans-=val[rt[1]],pop(rt[1]);
	printf("%lld",ans);
	return 0;
}

Compilation message (stderr)

fireworks.cpp: In function 'int main()':
fireworks.cpp:22:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   22 |  scanf("%lld%lld",&n,&m);
      |  ~~~~~^~~~~~~~~~~~~~~~~~
fireworks.cpp:24:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |   scanf("%lld%lld",&fa[i],&w[i]);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 19 / 19
• Subtask 3: 29 / 29
• Subtask 4: 45 / 45