题目链接：戳我

include

include

include

include

include

define MAXN 100010

using namespace std;
int n,m;
int a[MAXN<<2],rt[MAXN],fa[MAXN];
struct Node{int ch[2],val,ff,dis;}t[MAXN<<2];
inline int find(int x){return fa[x]==x?x:fa[x]=find(fa[x]);}
inline int merge(int x,int y)
{
if(t[x].val==-1) x=0;
if(t[y].val==-1) y=0;
if(x==0||y==0) return x+y;
if(t[x].val>t[y].val) swap(x,y);
t[x].ch[1]=merge(t[x].ch[1],y);
fa[t[x].ch[1]]=fa[t[x].ch[0]]=fa[x]=x;
if(t[t[x].ch[0]].dis<t[t[x].ch[1]].dis) swap(t[x].ch[0],t[x].ch[1]);
t[x].dis=t[t[x].ch[1]].dis+1;
return x;
}
inline int pop(int x)
{
fa[t[x].ch[0]]=t[x].ch[0];
fa[t[x].ch[1]]=t[x].ch[1];
t[x].val=-1;
int tt=merge(t[x].ch[0],t[x].ch[1]);
fa[x]=tt;
return tt;
}
int main()
{
#ifndef ONLINE_JUDGE
freopen("ce.in","r",stdin);
freopen("ce.out","w",stdout);
#endif
scanf("%d%d",&n,&m);
for(int i=1;i<=n;i++) scanf("%d",&t[i].val);
for(int i=1;i<=n;i++) fa[i]=i;
for(int i=1;i<=m;i++)
{
int op,x,y;
scanf("%d",&op);
if(op==1)
{
scanf("%d%d",&x,&y);
if(t[x].val==-1||t[y].val==-1) continue;
int a=find(x),b=find(y);
if(a!=b) merge(a,b);
}
else if(op==2)
{
scanf("%d",&x);
if(t[x].val==-1) {printf("-1\n");continue;}
int ff=find(x);
printf("%d\n",t[ff].val);
pop(ff);
}
}
return 0;
}

左偏树模板（带路径压缩）

原文：https://www.cnblogs.com/fengxunling/p/10650656.html