#include<bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define ll long long
#define pb push_back
const int N=3e5+50;
vector<int>E[N];
int n,q;
array<int,3>Qs[N];
struct DSU{
int par[N];
void Init(){for(int i=0;i<N;i++)par[i]=i;}
DSU(){Init();}
int FS(int u){if(par[u]==u)return u;return par[u]=FS(par[u]);}
void US(int u,int v){par[FS(u)]=v;}
}dsu;
struct SegTree{
int root,nc,lc[2*N],rc[2*N],sum[2*N],lazy[2*N];
void update(int &c,int ss,int se,int x){
if(!c)c=++nc,lazy[c]=-1;
if(x!=-1){
sum[c]=(se-ss+1)*x;
lazy[c]=x;
}
}
void push(int &c,int ss,int se){
if(!c)c=++nc,lazy[c]=-1;
int mid=ss+se>>1;
update(lc[c],ss,mid,lazy[c]);
update(rc[c],mid+1,se,lazy[c]);
lazy[c]=-1;
}
void Update(int &c,int ss,int se,int qs,int qe,int x){
if(!c)c=++nc,lazy[c]=-1;
if(qs>qe||qe<ss||se<qs)return;
if(qs<=ss&&se<=qe){update(c,ss,se,x);return;}
int mid=ss+se>>1;push(c,ss,se);
Update(lc[c],ss,mid,qs,qe,x);
Update(rc[c],mid+1,se,qs,qe,x);
sum[c]=sum[lc[c]]+sum[rc[c]];
}
int Get(int &c,int ss,int se,int qs,int qe){
if(!c)c=++nc,lazy[c]=-1;
if(qs>qe||qe<ss||se<qs)return 0;
if(qs<=ss&&se<=qe)return sum[c];
int mid=ss+se>>1;push(c,ss,se);
return Get(lc[c],ss,mid,qs,qe)+Get(rc[c],mid+1,se,qs,qe);
}
}ST;
int head[N],depth[N],sajz[N],par[N];
void DFS(int u,int p=0){
depth[u]=depth[p]+1;
par[u]=p;
for(auto &i:E[u])if(i==p){swap(i,E[u].back());break;}
if(p!=0)E[u].pop_back();
sajz[u]=1;
for(auto i:E[u])DFS(i,u),sajz[u]+=sajz[i];
}
int in[N],out[N],tajm;
void HLD(int u){
in[u]=++tajm;
int mx=0,v=0;
for(auto i:E[u])if(sajz[i]>mx)mx=sajz[i],v=i;
for(auto &i:E[u])if(i==v){swap(i,E[u][0]);break;}
if(head[u]==0)head[u]=u;
if(v>0)head[v]=head[u];
for(auto i:E[u])HLD(i);
out[u]=tajm;
}
int LCA(int u,int v){
while(head[u]!=head[v]){
if(depth[u]<depth[v])swap(u,v);
u=par[head[u]];
}
return depth[u]<depth[v]?u:v;
}
int Calc(int u,int c){
int res=0;
while(head[u]!=head[c]){
res+=ST.Get(ST.root,1,tajm,in[head[u]],in[u]);
u=par[head[u]];
}
res+=ST.Get(ST.root,1,tajm,in[c]+1,in[u]);
return res;
}
void Upd(int u,int c,int x){
while(head[u]!=head[c]){
ST.Update(ST.root,1,tajm,in[head[u]],in[u],0);
u=par[head[u]];
}
ST.Update(ST.root,1,tajm,in[c]+1,in[u],0);
}
int main(){
scanf("%i%i",&n,&q);
for(int i=1;i<=q;i++)scanf("%i%i%i",&Qs[i][0],&Qs[i][1],&Qs[i][2]);
for(int i=1;i<=q;i++){
auto [t,u,v]=Qs[i];
if(t==1&&dsu.FS(u)!=dsu.FS(v)){
dsu.US(u,v);
E[u].pb(v);
E[v].pb(u);
}
}
int root=n+1;
for(int i=1;i<=n;i++)if(dsu.FS(i)!=dsu.FS(root)){
dsu.US(i,root);
E[i].pb(root);
E[root].pb(i);
}
DFS(root);
HLD(root);
dsu.Init();
ST.Update(ST.root,1,tajm,1,tajm,1);
for(int i=1;i<=q;i++){
auto [t,u,v]=Qs[i];
if(t==1){
if(dsu.FS(u)!=dsu.FS(v))dsu.US(u,v);
else{
int c=LCA(u,v);
Upd(u,c,0);
Upd(v,c,0);
}
}
else{
if(dsu.FS(u)!=dsu.FS(v)){
int c=LCA(u,v);
int res=Calc(u,c)+Calc(v,c);
printf("%i\n",res);
}
else printf("-1\n");
}
}
return 0;
}
Compilation message (stderr)
road_development.cpp: In function 'int main()':
road_development.cpp:95:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
95 | scanf("%i%i",&n,&q);
| ~~~~~^~~~~~~~~~~~~~
road_development.cpp:96:31: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
96 | for(int i=1;i<=q;i++)scanf("%i%i%i",&Qs[i][0],&Qs[i][1],&Qs[i][2]);
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