RT
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
//#define int long long
const ll MAXN=2e6+5,MAXM=2e6+5;
ll n,m,k,x,y;
int col[MAXN];
struct edge{
int u,v,w,nxt;
int col_u,col_v;
bool operator < (const edge &oth)const{
return col_u==oth.col_u?col_v<oth.col_v:col_u<oth.col_u;
}
}e[MAXM],new_e[MAXM],ttt[MAXM];
ll ttt_cnt;
int head[MAXN],edge_num;
int head_new[MAXN],edge_num_new;
void add_edge(int From,int To){
edge_num++;
e[edge_num].u=From;
e[edge_num].col_u=col[From];
e[edge_num].v=To;
e[edge_num].col_v=col[To];
e[edge_num].nxt=head[From];
head[From]=edge_num;
return;
}
void add_edge_new(int From,int To,int Len){
edge_num_new++;
new_e[edge_num_new].u=From;
new_e[edge_num_new].col_u=col[From];
new_e[edge_num_new].v=To;
new_e[edge_num_new].col_v=col[To];
new_e[edge_num_new].w=Len;
new_e[edge_num_new].nxt=head_new[From];
head_new[From]=edge_num_new;
return;
}
vector<int> vec_col[MAXN];
vector<edge> vec_edge[MAXN];
bool check[MAXN];
int fa[MAXN];
int Find(int num){
return num==fa[num]?num:fa[num]=Find(fa[num]);
}
ll ans;
ll sum,cnt;
int p_col[MAXN],tot;
int rt[MAXN];
int rev[MAXN];
void paint(int now,bool now_c,int color){
if(p_col[now]!=-1||col[now]!=color)return;
p_col[now]=now_c;
rt[now]=tot;
for(int i=head[now];i;i=e[i].nxt){
if(p_col[e[i].v]!=-1||col[e[i].v]!=color)continue;
paint(e[i].v,now_c^1,color);
}
return;
}
map<int,bool> mp_rt;
int p_rev[MAXN];
struct node{
int id,now_c;
};
bool vvv[MAXN];
queue<node> q;
bool bfs(int st){
for(auto x:mp_rt)p_rev[x.first]=-1,vvv[x.first]=0;
p_rev[n+1]=-1,vvv[n+1]=0;
p_rev[st]=0;
while(q.size())q.pop();
q.push((node){st,0});
while(q.size()){
node now=q.front();
q.pop();
vvv[now.id]=1;
for(int i=head_new[now.id];i;i=new_e[i].nxt){
if(vvv[new_e[i].v]){
bool reg_rev=now.now_c^new_e[i].w;
if(p_rev[new_e[i].v]!=reg_rev)return 0;
continue;
}
p_rev[new_e[i].v]=p_rev[now.id]^new_e[i].w;
q.push((node){new_e[i].v,p_rev[new_e[i].v]});
}
}
return 1;
}
signed main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin>>n>>m>>k;
for(int i=1;i<=n;i++){
cin>>col[i];
vec_col[col[i]].push_back(i);
}
for(int i=1;i<=m;i++){
cin>>x>>y;
add_edge(x,y);
add_edge(y,x);
if(col[x]==col[y]){
vec_edge[col[x]].push_back(e[edge_num-1]);
vec_edge[col[x]].push_back(e[edge_num]);
}
}
for(int i=1;i<=k;i++){
for(ll x:vec_col[i-1])head_new[x]=0;
for(ll x:vec_col[i])fa[x]=x;
edge_num_new=0;
for(edge x:vec_edge[i])add_edge_new(x.u,x.v,0);
for(ll x:vec_col[i]){
ll res=new_e[head_new[x]].v;
if(check[i])break;
for(int j=head_new[x];j;j=new_e[j].nxt){
if(Find(new_e[j].v)==Find(x)){
check[i]=1;
break;
}
fa[Find(res)]=Find(new_e[j].v);
res=new_e[j].v;
}
}
sum+=check[i];
}
for(int i=1;i<=n+1;i++)p_col[i]=-1;
for(int i=1;i<=k;i++){
if(!check[i]){
for(auto x:vec_col[i]){
if(p_col[x]==-1){
tot++;
paint(x,0,i);
}
}
}
}
for(int i=1;i<=n;i++)rev[i]=-1;
// cout<<"tot "<<tot<<endl;
// cout<<"rt\n";
// for(int i=1;i<=n;i++)cout<<rt[i]<<" ";
// cout<<endl<<"col\n";
// for(int i=1;i<=n;i++)cout<<p_col[i]<<" ";
// cout<<endl;
sum=k-sum;
for(int i=1;i<=edge_num;i++)if(e[i].col_u!=e[i].col_v)ttt[++ttt_cnt]=e[i];
for(int i=1;i<=n+2;i++)head[i]=0,head_new[i]=0;
edge_num=edge_num_new=0;
for(int i=1;i<=ttt_cnt;i++)add_edge(ttt[i].u,ttt[i].v);
sort(e+1,e+1+edge_num);
ll qaq=0;
for(int i=1,j;i<=edge_num;i=j+1){
if(mp_rt.size())for(auto x:mp_rt)head_new[x.first]=0,p_rev[x.first]=0;
head_new[n+1]=0;
edge_num_new=0;
mp_rt.clear();
for(j=i;e[j].col_u==e[i].col_u&&e[j].col_v==e[i].col_v&&j<=edge_num;j++);
j--;
if(e[i].col_u>e[i].col_v||check[e[i].col_u]||check[e[i].col_v])continue;
cnt++;
qaq=1;
for(int k=i;k<=j;k++){
ll rt_u=rt[e[k].u],rt_v=rt[e[k].v];
mp_rt[rt_u]=mp_rt[rt_v]=1;
p_rev[rt_u]=p_rev[rt_v]=-2;
if(p_col[e[k].u]==p_col[e[k].v])add_edge_new(rt_u,rt_v,1),add_edge_new(rt_v,rt_u,1);//rev
else add_edge_new(rt_u,n+1,1),add_edge_new(rt_v,n+1,1),add_edge_new(n+1,rt_u,1),add_edge_new(n+1,rt_v,1),p_rev[n+1]=-2;//nrev
}
bool fl=1;
for(auto x:mp_rt){
if(p_rev[x.first]!=-2)continue;
fl&=bfs(x.first);
}
ans+=fl;
}
ans=ans-cnt+(1ll*sum*(sum-1))/2ll;
// if(ans==494372)ans=494070;//here
cout<<ans;
return 0;
}
给个hack,或者指出错误都可以/dk