#include<algorithm>
#include<cstdio>
namespace IO{
const int ARR_SIZE=1<<20;
#define gc() ((IO::si!=IO::ti||(IO::ti=(IO::si=IO::input)+fread(IO::input,1,IO::ARR_SIZE,stdin))),IO::si!=IO::ti?*(IO::si++):EOF)
#define pc(ch) ((IO::o.so!=IO::o.to||(fwrite(IO::o.output,1,IO::ARR_SIZE,stdout),IO::o.so=IO::o.output)),*(IO::o.so++)=ch)
char input[ARR_SIZE],*si=input,*ti=input;
struct Output_Stream{
char output[ARR_SIZE],*so=output,*to=output+ARR_SIZE;
~Output_Stream(){
if(so==output)return;
fwrite(output,1,so-output,stdout);
so=output;
}
}o;
template<typename T>
void read(T&num){
int ch=gc();
num=0;
while(ch<48||ch>57)ch=gc();
while(ch>=48&&ch<=57)num=(num<<3)+(num<<1)+(ch^48),ch=gc();
}
template<typename T>
void write(T a){
static int ch[50],cnt=0;
if(a==0)pc('0');
while(a)ch[++cnt]=a%10|48,a/=10;
while(cnt)pc(ch[cnt--]);
}
}
using IO::read;
using IO::write;
typedef long long ll;
const int maxn=100000;
int n,t[maxn+1],p[maxn+1];
int head[maxn+1],total;
struct Edge{
int to,next;
}e[(maxn-1)*2+1];
void add(const int u,const int v){
e[++total]=Edge{v,head[u]};
head[u]=total;
}
int fa[maxn+1],val[maxn+1],size[maxn+1];
ll ans;
int find(const int x){
return x==fa[x]?x:fa[x]=find(fa[x]);
}
void merge(int x,int y){
x=find(x),y=find(y);
ans+=val[x]+val[y];
if(size[x]>size[y]){
fa[y]=x;
val[x]=std::max(val[x],val[y]);
size[x]+=size[y];
}else{
fa[x]=y;
val[y]=std::max(val[y],val[x]);
size[y]+=size[x];
}
}
int main(){
read(n);
for(int i=1;i<=n;i++)read(t[i]);
for(int i=1;i<=n;i++)p[i]=i;
memcpy(fa+1,p+1,sizeof(int)*n);
memcpy(val+1,t+1,sizeof(int)*n);
for(int i=1;i<=n;i++)size[i]=1;
std::sort(p+1,p+n+1,[](const int x,const int y){
return t[x]<t[y];
});
for(int i=1,x,y;i<n;i++){
read(x),read(y);
add(x,y),add(y,x);
}
for(int i=1;i<=n;i++){
const int u=p[i];
for(int i=head[u];i;i=e[i].next){
const int v=e[i].to;
if(t[v]<t[u]||(t[v]==t[u]&&v<u))merge(u,v);
}
}
write(ans),pc('\n');
return 0;
}
Compilation message
sjekira.cpp: In function 'int main()':
sjekira.cpp:66:2: error: 'memcpy' was not declared in this scope
66 | memcpy(fa+1,p+1,sizeof(int)*n);
| ^~~~~~
sjekira.cpp:3:1: note: 'memcpy' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
2 | #include<cstdio>
+++ |+#include <cstring>
3 | namespace IO{
