bzoj2038（莫队）

版权声明：写了自己看的，看不懂不能怪我emmmm。 https://blog.csdn.net/qq_40858062/article/details/82015880

题目链接：https://www.lydsy.com/JudgeOnline/problem.php?id=2038

思路：。。模板题

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <bitset>
#include <cmath>
#include <cctype>
#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <queue>
#include <map>
#include <set>
#include <sstream>
#include <iomanip>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const ll inff = 0x3f3f3f3f3f3f3f3f;
#define FOR(i,a,b) for(int i(a);i<=(b);++i)
#define FOL(i,a,b) for(int i(a);i>=(b);--i)
#define REW(a,b) memset(a,b,sizeof(a))
#define inf int(0x3f3f3f3f)
#define si(a) scanf("%d",&a)
#define sl(a) scanf("%I64d",&a)
#define sd(a) scanf("%lf",&a)
#define ss(a) scanf("%s",a)
#define mod ll(998244353)
#define pb push_back
#define eps 1e-6
#define lc d<<1
#define rc d<<1|1
#define Pll pair<ll,ll>
#define P pair<int,int>
#define pi acos(-1)
struct as{
int l,r,d;
ll x,y;}d[50008];
int n,m,b[50008],a[50008],zz,qw[50008];
ll s,er;
bool cmp(as a,as c){return b[a.l]==b[c.l]?a.r<c.r:a.l<c.l;}
bool cmp1(as a,as b){return a.d<b.d;}
void add(int x,int y){s-=1ll*qw[a[x]]*qw[a[x]],qw[a[x]]+=y,s+=1ll*qw[a[x]]*qw[a[x]];}
int main()
{
    cin.tie(0);
    cout.tie(0);
    cin>>n>>m;
    zz=sqrt(n);
    FOR(i,1,n) si(a[i]),b[i]=i/zz+1;
    FOR(i,1,m) si(d[i].l),si(d[i].r),d[i].d=i;
    sort(d+1,d+m+1,cmp);
    int l=1,r=0;
    FOR(i,1,m)
    {
        while(l<d[i].l)add(l,-1),l++;
        while(l>d[i].l)add(l-1,1),l--;
        while(r<d[i].r)add(r+1,1),r++;
        while(r>d[i].r)add(r,-1),r--;
        d[i].x=s-1ll*(d[i].r-d[i].l+1);
        d[i].y=1ll*(d[i].r-d[i].l)*(d[i].r-d[i].l+1);
        er=__gcd(d[i].x,d[i].y);d[i].x/=er,d[i].y/=er;
    }
    sort(d+1,d+m+1,cmp1);
    FOR(i,1,m)
     printf("%lld/%lld\n",d[i].x,d[i].y);
    return 0;
}