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| #include<cstdio> #include<cstring> #include<algorithm> #include<iostream> #include<queue> #include<map> #include<stack> #include<cmath> #include<set> #include<bitset> #include<assert.h> #define inc(i,l,r) for(int i=l;i<=r;i++) #define dec(i,l,r) for(int i=l;i>=r;i--) #define link(x) for(edge *j=h[x];j;j=j->next) #define mem(a) memset(a,0,sizeof(a)) #define ll long long #define eps 1e-6 #define succ(x) (1<<x) #define lowbit(x) (x&(-x)) #define sqr(x) ((x)*(x)) #define mid (x+y)/2 #define NM 100005 #define nm 200005 #define pi 3.1415926535897931 using namespace std; ll read(){ ll x=0,f=1;char ch=getchar(); while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();} while(isdigit(ch))x=x*10+ch-'0',ch=getchar(); return f*x; }
struct edge{int x,t;edge*next;}e[nm],*h[NM]; int n,m,b[NM],v[NM],ans[nm],_v[NM]; ll s;
int main(){ while(~scanf("%d%d",&n,&m)){ inc(i,1,n)h[i]=0,b[i]=0,v[i]=0;s=0; inc(i,1,m)e[i].x=read(),e[i].t=read(),b[e[i].x]++,b[e[i].t]++,ans[i]=0; inc(i,1,m){ if(b[e[i].t]>b[e[i].x]||(b[e[i].x]==b[e[i].t]&&e[i].x>e[i].t))swap(e[i].x,e[i].t); e[i].next=h[e[i].x];h[e[i].x]=e+i; } #define _link(x) for(edge *k=h[x];k;k=k->next) inc(i,1,n){ link(i)v[j->t]=i,_v[j->t]=j-e; link(i){ _link(j->t)if(v[k->t]==i)ans[j-e]++,ans[k-e]++,ans[_v[k->t]]++; } } inc(i,1,m)s+=1ll*ans[i]*(ans[i]-1)/2; printf("%lld\n",s); } return 0; }
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