Language: C++

#include<bits/stdc++.h>
#define pb push_back
#define ld long double
#define mp make_pair
#define vl vector<ll> 
#define vd vector<double>
#define vld vector<long double>
#define ll int
#define pl pair<ll, ll>
#define all(a) a.begin(), a.end()
#define forr(i, n) for(ll i=0; i<n; i++) 
#define forr1(i, n) for(ll i=1; i<=n; i++)
using namespace std;
const ld PI =3.1415926535897923846;
const ll MOD = 1000000007;
const ll N=998244353;
ll power(ll x,ll n){ll res=1;while(n>0){if(n&1) res=res*x%MOD;x=x*x%MOD;n>>=1;}return res;}
ll modinverse(ll a){return power(a, MOD-2);}
struct node{
    ll answer;
    unordered_map<ll, ll> mp1;
}segtree[2048679];
vl color;
node util(node x, node y)
{
    node ans;
    unordered_map<ll, ll>:: iterator itr;
    for(itr=(x.mp1).begin(); itr!=(x.mp1).end(); itr++)
    {
        ll col=itr->first;
        ans.mp1[col]++;
    }
    for(itr=(y.mp1).begin(); itr!=(y.mp1).end(); itr++)
    {
        ll col=itr->first;
        ans.mp1[col]++;
    }
    ans.answer=(ll)((ans.mp1).size());
    return ans;
}
node Query(ll start, ll end, ll r1, ll r2, ll put)
{
    if(start>=r1&&end<=r2)
    return segtree[put];
    node sex;
    map<ll, ll> mp10;
    sex.mp1=mp10;
    sex.answer=0;
    if(start>r2||end<r1)
    return sex;
    ll mid=start+(end-start)/2;
    return util(Query(start, mid, r1, r2, 2*put+1), Query(mid+1, end, r1, r2, 2*put+2));
}
node constructTree(ll start, ll end, ll put)
{
    if(start==end)
    {
        map<ll, ll> fuck;
        fuck[color[start]]++;
        segtree[put].answer=1;
        segtree[put].mp1=fuck;
        return segtree[put];
    }
    ll mid=start+(end-start)/2;
    segtree[put]=util(constructTree(start, mid, 2*put+1), constructTree(mid+1, end, 2*put+2));
    return segtree[put];
}
void solve()
{
    ll n, q;
	cin>>n>>q;
	color.resize(n);
	forr(i, n)
	{
	    cin>>color[i];
	}
	ll x=(ll)ceil((log2(n)));
    x=(ll)pow(2, x);
    constructTree(0, n-1, 0);
	forr(i, q)
	{
	    ll lef, rig;
	    cin>>lef>>rig;
	    --lef;
	    --rig;
	    node lala=Query(0, n-1, lef, rig, 0);
        cout<<lala.answer<<endl;
	}
}
int main()
{
	#ifndef ONLINE_JUDGE
        // for getting input from input.txt
        freopen("input.txt", "r", stdin);
        // for writing output to output.txt
        freopen("output.txt", "w", stdout);
    #endif
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    ll test=1;
    //cin>>test;
    while(test--)
    {
        solve();
    }
    cerr << "Time : " << 1000 * ((double)clock()) / (double)CLOCKS_PER_SEC << "ms\n";
}

Compiler output:
a.cc: In function 'node Query(int, int, int, int, int)':
a.cc:47:13: error: no match for 'operator=' (operand types are 'std::unordered_map<int, int>' and 'std::map<int, int>')
   47 |     sex.mp1=mp10;
      |             ^~~~
In file included from /usr/include/c++/14/unordered_map:41,
                 from /usr/include/c++/14/functional:63,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:53,
                 from a.cc:1:
/usr/include/c++/14/bits/unordered_map.h:279:7: note: candidate: 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(const std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>&) [with _Key = int; _Tp = int; _Hash = std::hash<int>; _Pred = std::equal_to<int>; _Alloc = std::allocator<std::pair<const int, int> >]'
  279 |       operator=(const unordered_map&) = default;
      |       ^~~~~~~~
/usr/include/c++/14/bits/unordered_map.h:279:17: note:   no known conversion for argument 1 from 'std::map<int, int>' to 'const std::unordered_map<int, int>&'
  279 |       operator=(const unordered_map&) = default;
      |                 ^~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/unordered_map.h:283:7: note: candidate: 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>&&) [with _Key = int; _Tp = int; _Hash = std::hash<int>; _Pred = std::equal_to<int>; _Alloc = std::allocator<std::pair<const int, int> >]'
  283 |       operator=(unordered_map&&) = default;
      |       ^~~~~~~~
/usr/include/c++/14/bits/unordered_map.h:283:17: note:   no known conversion for argument 1 from 'std::map<int, int>' to 'std::unordered_map<int, int>&&'
  283 |       operator=(unordered_map&&) = default;
      |                 ^~~~~~~~~~~~~~~
/usr/include/c++/14/bits/unordered_map.h:297:7: note: candidate: 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(std::initializer_list<typename std::_Hashtable<_Key, std::pair<const _Key, _Val>, _Alloc, std::__detail::_Select1st, _Pred, _Hash, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<std::__not_<std::__and_<std::__is_fast_hash<_Hash>, std::__is_nothrow_invocable<const _Hash&, const _Key&> > >::value, false, true> >::value_type>) [with _Key = int; _Tp = int; _Hash = std::hash<int>; _Pred = std::equal_to<int>; _Alloc = std::allocator<std::pair<const int, int> >; typename std::_Hashtable<_Key, std::pair<const _Key, _Val>, _Alloc, std::__detail::_Select1st, _Pred, _Hash, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<std::__not_<std::__and_<std::__is_fast_hash<_Hash>, std::__is_nothrow_invocable<const _Hash&, const _Key&> > >::value, false, true> >::value_type = std::pair<const int, int>]'
  297 |       operator=(initializer_list<value_type> __l)
      |       ^~~~~~~~
/usr/include/c++/14/bits/unordered_map.h:297:46: note:   no known conversion for argument 1 from 'std::map<int, int>' to 'std::initializer_list<std::pair<const int, int> >'
  297 |       operator=(initializer_list<value_type> __l)
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
a.cc: In function 'node constructTree(int, int, int)':
a.cc:61:26: error: no match for 'operator=' (operand types are 'std::unordered_map<int, int>' and 'std::map<int, int>')
   61 |         segtree[put].mp1=fuck;
      |                          ^~~~
/usr/include/c++/14/bits/unordered_map.h:279:7: note: candidate: 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(const std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>&) [with _Key = int; _Tp = int; _Hash = std::hash<int>; _Pred = std::equal_to<int>; _Alloc = std::allocator<std::pair<const int, int> >]'
  279 |       operator=(const unordered_map&) = default;
      |       ^~~~~~~~
/usr/include/c++/14/bits/unordered_map.h:279:17: note:   no known conversion for argument 1 from 'std::map<int, int>' to 'const std::unordered_map<int, int>&'
  279 |       operator=(const unordered_map&) = default;
      |                 ^~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/unordered_map.h:283:7: note: candidate: 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>&&) [with _Key = int; _Tp = int; _Hash = std::hash<int>; _Pred = std::equal_to<int>; _Alloc = std::allocator<std::pair<const int, int> >]'
  283 |       operator=(unordered_map&&) = default;
      |       ^~~~~~~~
/usr/include/c++/14/bits/unordered_map.h:283:17: note:   no known conversion for argument 1 from 'std::map<int, int>' to 'std::unordered_map<int, int>&&'
  283 |       operator=(unordered_map&&) = default;
      |                 ^~~~~~~~~~~~~~~
/usr/include/c++/14/bits/unordered_map.h:297:7: note: candidate: 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(std::initializer_list<typename std::_Hashtable<_Key, std::pair<const _Key, _Val>, _Alloc, std::__detail::_Select1st, _Pred, _Hash, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<std::__not_<std::__and_<std::__is_fast_hash<_Hash>, std::__is_nothrow_invocable<const _Hash&, const _Key&> > >::value, false, true> >::value_type>) [with _Key = int; _Tp = int; _Hash = std::hash<int>; _Pred = std::equal_to<int>; _Alloc = std::allocator<std::pair<const int, int> >; typename std::_Hashtable<_Key, std::pair<const _Key, _Val>, _Alloc, std::__detail::_Select1st, _Pred, _Hash, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<std::__not_<std::__and_<std::__is_fast_hash<_Hash>, std::__is_nothrow_invocable<const _Hash&, const _Key&> > >::value, false, true> >::value_type = std::pair<const int, int>]'
  297 |       operator=(initializer_list<value_type> __l)
      |       ^~~~~~~~
/usr/include/c++/14/bits/unordered_map.h:297:46: note:   no known conversion for argument 1 from 'std::map<int, int>' to 'std::initializer_list<std::pair<const int, int> >'
  297 |       operator=(initializer_list<value_type> __l)
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~