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| #include <bits/stdc++.h>
using namespace std;
const double eps = 1e-10;
const double pi = 3.1415926535897932384626433832795;
const double eln = 2.718281828459045235360287471352;
#define f(i, a, b) for (int i = a; i <= b; i++)
#define scan(x) scanf("%d", &x)
#define mp make_pair
#define pb push_back
#define lowbit(x) (x&(-x))
#define fi first
#define se second
#define SZ(x) int((x).size())
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define summ(a) (accumulate(all(a), 0ll))
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;
using ll=long long;
ll n,m,k,a[(int)5e4+9],ans[(int)5e4+9],l=1,r,sum,s[(int)5e4+9],sz,id[(int)5e4+9],l1[(int)5e4+9],r1[(int)5e4+9];
struct line{
ll l,r,num;
}q[(int)5e4+9];
bool cmp(line x,line y){
return id[x.r]==id[y.r]?x.l<y.l:x.r<y.r;
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(0);
cin>>n>>m;
sz=n/sqrt(m*2/3);
for(int i=1;i<=n;++i)cin>>a[i],id[i]=(i-1)/sz+1;
for(int i=1;i<=m;++i)cin>>q[i].l>>q[i].r,q[i].num=i,l1[i]=q[i].l,r1[i]=q[i].r;
sort(q+1,q+1+m,cmp);
for(int i=1;i<=m;++i){
while(l<q[i].l)sum-=s[a[l]]*(s[a[l]]-1)/2,s[a[l]]-=1,sum+=s[a[l]]*(s[a[l]]-1)/2,l+=1;
while(l>q[i].l)l-=1,sum-=s[a[l]]*(s[a[l]]-1)/2,s[a[l]]+=1,sum+=s[a[l]]*(s[a[l]]-1)/2;
while(r<q[i].r)r+=1,sum-=s[a[r]]*(s[a[r]]-1)/2,s[a[r]]+=1,sum+=s[a[r]]*(s[a[r]]-1)/2;
while(r>q[i].r)sum-=s[a[r]]*(s[a[r]]-1)/2,s[a[r]]-=1,sum+=s[a[r]]*(s[a[r]]-1)/2,r-=1;
ans[q[i].num]=sum;
}
for(int i=1,x;i<=m;++i){
x=std::gcd(ans[i],(r1[i]-l1[i]+1)*(r1[i]-l1[i])/2);
if(l1[i]==r1[i])cout<<"0/1\n";
else cout<<ans[i]/x<<"/"<<(r1[i]-l1[i]+1)*(r1[i]-l1[i])/2/x<<"\n";
}
return 0;
}
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