uoj279温暖会指引我们前行
暖气来啦~
动态树维护最大生成树裸题
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#include<iostream> #include<cstdio> #include<cstdlib> #include<cstring> #include<cmath> #include<algorithm> using namespace std; inline int read() { int x=0,f=1;char ch=getchar(); while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();} while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();} return x*f; } const int maxn=400010; int es[maxn][2]; int n,m; int rt,Size; struct LCT { int son[maxn][2],f[maxn],val[maxn],size[maxn],cnt[maxn],rev[maxn],st[maxn]; int t[maxn],len[maxn],mn[maxn],sum[maxn]; inline void update(int x) { int &o=x,lch=son[x][0],rch=son[x][1]; mn[o]=x;sum[o]=len[o]; if(son[x][0]) { if(t[mn[lch]]<t[mn[x]]) mn[o]=mn[lch]; sum[o]+=sum[lch]; } if(son[x][1]) { if(t[mn[rch]]<t[mn[x]]) mn[o]=mn[rch]; sum[o]+=sum[rch]; } } inline int isroot(int x){return son[f[x]][0]!=x && son[f[x]][1]!=x;} inline void rotate(int x) { int y=f[x],z=f[y],l,r; if(son[y][0]==x)l=0; else l=1;r=l^1; if(!isroot(y)) { if(son[z][0]==y)son[z][0]=x; else son[z][1]=x; } f[x]=z;f[y]=x;f[son[x][r]]=y; son[y][l]=son[x][r];son[x][r]=y; update(y); } inline void pushdown(int id) { int lch=son[id][0],rch=son[id][1]; if(rev[id]) { rev[id]^=1;rev[lch]^=1;rev[rch]^=1; swap(son[id][0],son[id][1]); } } inline void Splay(int x) { int top=0;st[++top]=x; for(int i=x;!isroot(i);i=f[i])st[++top]=f[i]; for(int i=top;i;i--)pushdown(st[i]); while(!isroot(x)) { int y=f[x],z=f[y]; if(!isroot(y)) { if(son[y][0]==x^son[z][0]==y)rotate(x); else rotate(y); } rotate(x); } update(x); } inline void access(int x) { int t=0; while(x) { Splay(x); son[x][1]=t; t=x; x=f[x]; update(x); } } inline void makert(int x){access(x);Splay(x);rev[x]^=1;} inline void link(int x,int y){makert(x);f[x]=y;} inline void cut(int x,int y){makert(x);access(y);Splay(y);son[y][0]=f[x]=0;update(y);} inline int findf(int x) { access(x);Splay(x); int y=x; while(son[y][0])y=son[y][0]; return y; } }Tree; char opt[10]; int main() { scanf("%d%d",&n,&m); int k,x,y,z; for(int i=1;i<=n;i++)Tree.t[i]=2147483233; while(m--) { scanf("%s",opt); if(opt[0]=='f') { scanf("%d%d%d",&z,&x,&y);z++,x++,y++; z+=n;es[z][0]=x,es[z][1]=y; scanf("%d%d",&Tree.t[z],&Tree.len[z]); if(Tree.findf(x)!=Tree.findf(y)){Tree.link(z,x),Tree.link(z,y);} else { Tree.makert(x);Tree.access(y);Tree.Splay(y); if(Tree.t[Tree.mn[y]]<Tree.t[z]) { k=Tree.mn[y];Tree.cut(k,es[k][0]);Tree.cut(k,es[k][1]); Tree.link(z,x),Tree.link(z,y); } } } else if(opt[0]=='m') { scanf("%d%d",&x,&y);x++,y++; if(Tree.findf(x)!=Tree.findf(y))puts("-1"); else { Tree.makert(x);Tree.access(y);Tree.Splay(y); printf("%d\n",Tree.sum[y]); } } else { scanf("%d%d",&x,&y);x++; x+=n;Tree.Splay(x);Tree.len[x]=y;Tree.update(x); } } }