Language: C++

#pragma GCC optimize("Ofast")
#include<bits/stdc++.h>
using namespace::std;
//struct __INIT{__INIT(){cin.tie(0);ios::sync_with_stdio(false);cout<<fixed<<setprecision(15);}} __init;
__attribute__((constructor))
void init(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	cout<<fixed<<setprecision(15);
}
// random_device rd;
// mt19937 mt(rd());
// #include <boost/numeric/interval.hpp>
// #include <boost/numeric/interval/io.hpp>
// #include <boost/intrusive/rbtree.hpp>
// #include <boost/dynamic_bitset.hpp>
// #include <boost/geometry.hpp>
// #include <boost/geometry/geometries/linestring.hpp>
// #include <boost/geometry/geometries/polygon.hpp>
// #include <boost/geometry/geometries/point_xy.hpp>
// #include <boost/math/tools/minima.hpp>
// using boost::math::tools::brent_find_minima;
// #include <boost/multiprecision/cpp_dec_float.hpp>
// #include <boost/multiprecision/cpp_int.hpp>
// namespace mp = boost::multiprecision;
// typedef mp::number<mp::cpp_dec_float<256>> cdouble;
// typedef mp::cpp_int cint;

#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/priority_queue.hpp>
#include<ext/pb_ds/tag_and_trait.hpp>
template<typename T=long long>using pbds=__gnu_pbds::tree<T,__gnu_pbds::null_type,less<T>,__gnu_pbds::rb_tree_tag,__gnu_pbds::tree_order_statistics_node_update>;
template<typename T=long long>using pbds_map=__gnu_pbds::tree<T,T,less<T>,__gnu_pbds::rb_tree_tag,__gnu_pbds::tree_order_statistics_node_update>;
template<typename T=long long>using pqueue =__gnu_pbds::priority_queue<T, less<T>,__gnu_pbds::rc_binomial_heap_tag>;
typedef long long lint;
typedef long long ll;
typedef long double ldouble;
typedef vector<lint> vec;
typedef vector<vector<lint>> mat;
typedef vector<vector<vector<lint>>> mat3;
typedef vector<double> dvec;
typedef vector<vector<double>> dmat;
typedef vector<vector<vector<double>>> dmat3;
typedef vector<string> svec;
typedef vector<vector<string>> smat;
typedef vector<vector<vector<string>>> smat3;
typedef vector<pair<lint,lint>> pvec;
typedef vector<vector<pair<lint,lint>>> pmat;
typedef vector<vector<vector<pair<lint,lint>>>> pmat3;
#define rep(i, n) for(lint i = 0; i < (lint)(n); i++)
#define irep(i) for(lint i = 0;; i++)
#define irep1(i) for(lint i = 1;; i++)
#define irep2(i) for(lint i = 2;; i++)
#define rrep(i, n) for(lint i = (lint)(n-1); i >-1; i--)
#define rrepi(i,a,b) for(lint i = (lint)(b-1); i >a-1; i--)
#define repi(i,a,b) for(lint i=lint(a);i<lint(b);i++)
#define rep2(i,a,b,c) for(lint i=lint(a);i>lint(b);i+=c)
#define all(x) (x).begin(),(x).end()
#define PI 3.141592653589793
#define dist(x1,y1,x2,y2) (pow(pow(x2-x1,2)+pow(y2-y1,2),0.5))
#define output(v) do{bool f=0;for(auto i:v){cout<<(f?" ":"");if(i>INF/2)cout<<"INF";else cout<<i;f=1;}cout<<"\n";}while(0);
#define output2(v) for(auto j:v)output(j);
#define _output(v) do{bool f=0;rep(i,v.size()){cout<<(f?" ":"");f=1;cout<<v[i];}cout<<"\n";}while(0)
#define _output2(v) rep(j,v.size()){_output(v[j]);}
#define input(a,n) lint n;cin>>n;vector<lint>a(n);rep(i,n)cin>>a[i];
#define SUM(v) accumulate(all(v),0LL)
#define INF (1LL<<60)
#define IINF (1<<30)
#define EPS (1e-10)
#define LINF 9223372036854775807
//#define MOD 998244353LL
#define MOD 1000000007LL
#define endl "\n"
auto Y=[&](auto f){return[&](auto... args){return f(f, args...);};};
template<typename T=lint>T in(){return *istream_iterator<T>(cin);}
template<typename T=lint>inline T gcd(T a,T b){return b?gcd(b,a%b):a;}
template<typename T=lint>inline T lcm(T a,T b){return a/gcd(a,b)*b;}
template<typename T=lint>inline T add(T a,T b){return a+b;}
template<typename T=lint>inline T minq(T a,T b){return min(a,b);}
inline bool chmin(auto& s,const auto& t){bool res=s>t;s=min(s,t);return res;}
inline bool chmax(auto& s,const auto& t){bool res=s<t;s=max(s,t);return res;}
vector<lint> dx={-1,1,0,0,1,1,-1,-1};
vector<lint> dy={0,0,-1,1,1,-1,1,-1};

class segment2d{
    template<typename T,typename E>
    class AVL_map{
        struct node;
        using np=node*;
        struct node{
            T key;E val;E cal;
            int cnt=1;
            int dep=0;
            np ch[2]={nullptr,nullptr};
            node(T key,E val):key(key),val(val){}
        };
        bool is_multi=true;
        np root=nullptr;
        inline int count(np t){return t?t->cnt:0;}
        inline int depth(np t){return t?t->dep:0;}
        inline E calc(np t){return t?t->cal:e;}
        inline np update(np& t,bool f=1){
            if(!t)return t;
            t->cnt=count(t->ch[0])+1+count(t->ch[1]);
            t->dep=max(depth(t->ch[0]),depth(t->ch[1]))+1;
            if(func){
                t->cal=e;
                if(t->ch[0])t->cal=func(t->cal,t->ch[0]->val);
                t->cal=func(t->cal,t->val);
                if(t->ch[1])t->cal=func(t->cal,t->ch[1]->val);
            }
            if(f&&abs(depth(t->ch[0])-depth(t->ch[1]))==2){
                rebuild(t,depth(t->ch[0])<depth(t->ch[1]));
            }
            return t;
        }
        using F=function<E(E,E)>;
        F func;E e;
        public:
        AVL_map(){}
        AVL_map(bool f){is_multi=f;}
        AVL_map(F f,E e):func(f),e(e){}
        inline void insert(T key,E val){insert(key,val,root);}
        inline void erase(T key){erase(key,root);}
        inline int lower_bound(T key){return lower_bound(key,root);}
        inline int upper_bound(T key){return upper_bound(key,root);}
        inline int count(T key){return upper_bound(key,root)-lower_bound(key,root);}
        inline int size(){return count(root);}
        inline T find_by_order(int idx){assert(0<=idx&&idx<size());return find_by_order(idx,root);}
        inline T operator[](int idx){return find_by_order(idx);}
        inline void allow_multi(bool f){is_multi=f;}
        inline E get_sum_by_order(int l,int r){return get_sum_by_order(l,r,-1,root);}
        inline E get_sum(T l,T r){return get_sum(l,r,-1,root);}
        private:
        E get_sum(T l,T r,int p,np t){
            if(!t)return e;
            bool f=l<=t->key&&t->key<r;
            if(r<=t->key)return get_sum(l,r,-1,t->ch[0]);
            if(l>t->key)return get_sum(l,r,-1,t->ch[1]);
            E l_val=(f&&p==1)?calc(t->ch[0]):get_sum(l,r,0,t->ch[0]);
            E r_val=(f&&p==0)?calc(t->ch[1]):get_sum(l,r,1,t->ch[1]);
            return func(func(l_val,f?t->val:e),r_val);
        }
        E get_sum_by_order(int l,int r,int p,np t){
            if(!t)return e;
            int idx=count(t->ch[0]);
            bool f=l<=idx&&idx<r;
            if(r<=idx)return get_sum_by_order(l,r,-1,t->ch[0]);
            if(l>idx)return get_sum_by_order(l-idx-1,r-idx-1,-1,t->ch[1]);
            E l_val=(f&&p==1)?calc(t->ch[0]):get_sum_by_order(l,r,0,t->ch[0]);
            E r_val=(f&&p==0)?calc(t->ch[1]):get_sum_by_order(l-idx-1,r-idx-1,1,t->ch[1]);
            return func(func(l_val,f?t->val:e),r_val);
        }
        void insert(T key,E val,np& t){
            if(!t)t=new node(key,val);
            else if(!is_multi&&key==t->key)return;
            else if(key<=t->key)insert(key,val,t->ch[0]);
            else if(key>t->key)insert(key,val,t->ch[1]);
            update(t);
        }
        void erase(T key,np& t){
            if(!t)return;
            else if(key==t->key){
                if(!t->ch[0]||!t->ch[1])t=t->ch[0]?t->ch[0]:t->ch[1];
                else move_down(t->ch[0],t);
            }
            else if(key<t->key)erase(key,t->ch[0]);
            else if(key>t->key)erase(key,t->ch[1]);
            update(t);
        }
        void move_down(np& t,np& p){
            if(t->ch[1])move_down(t->ch[1],p);
            else p->key=t->key,t=t->ch[0];
            update(t);
        }
        int lower_bound(T key,np t){
            if(!t)return 0;
            if(key<=t->key)return lower_bound(key,t->ch[0]);
            else return count(t->ch[0])+1+lower_bound(key,t->ch[1]);
        }
        int upper_bound(T key,np t){
            if(!t)return 0;
            if(key<t->key)return upper_bound(key,t->ch[0]);
            else return count(t->ch[0])+1+upper_bound(key,t->ch[1]);
        }
        E find_by_order(int idx,np t){
            if(idx==count(t->ch[0]))return t->val;
            else if(idx<count(t->ch[0]))return find_by_order(idx,t->ch[0]);
            else return find_by_order(idx-count(t->ch[0])-1,t->ch[1]);
        }
        np rot(np t){
            int b=depth(t->ch[0])<depth(t->ch[1]);
            if(depth(t->ch[0])==depth(t->ch[1]))return t;
            np s=t->ch[b];
            t->ch[b]=s->ch[1-b];
            s->ch[1-b]=t;
            update(t,0);update(s,0);
            return s;
        }
        void rebuild(np& t,int b){
            if(t->ch[b]&&depth(t->ch[b]->ch[b])<depth(t->ch[b]->ch[1-b])){
                t->ch[b]=rot(t->ch[b]);
            }
            t=rot(update(t,0));
        }
    };
	struct node;
	using np=node*;
	struct node{
		AVL_map<lint,lint> val=AVL_map<lint,lint>([](lint s,lint t){return s+t;},0);
		np ch[2]={nullptr,nullptr};
		node(){}
	};
	np root=nullptr;
	lint sz=1;
	public:
	segment2d(lint n){
		while(sz<n)sz<<=1;
	}
	inline void insert(lint x,lint y,lint val){insert(x,y,val,root,0,sz);}
	inline lint get(lint xl,lint yl,lint xr,lint yr){return get(xl,xr,yl,yr,root,0,sz);}
	private:
	void insert(lint x,lint y,lint val,np& t,lint l,lint r){
		if(l<=x&&x<r){
			if(!t)t=new node();
			t->val.insert(y,val);
			if(r-l>1){
				insert(x,y,val,t->ch[0],l,(l+r)/2);
				insert(x,y,val,t->ch[1],(l+r)/2,r);
			}
		}
	}
	lint get(lint a,lint b,lint c,lint d,np t,lint l,lint r){
		if(!t||b<=l||r<=a){
			return 0;
		}else if(a<=l&&r<=b){
			return t->val.get_sum(c,d);
		}else{
			return get(a,b,c,d,t->ch[0],l,(l+r)/2)+get(a,b,c,d,t->ch[1],(l+r)/2,r);
		}
	}
};

int main(){
    lint n,m,q;
	cin>>n>>m>>q;
    segment2d seg(n);
    rep(i,m){
		lint s,t;
		cin>>s>>t;
		s--;t--;
        seg.insert(s,t,1);
    }
    rep(i,q){
		lint p,q;
		cin>>p>>q;
		p--;q--;
        cout<<seg.get(p,0,n,q+1)<<endl;
    }
}

Compiler output:
a.cc:75:9: error: non-local lambda expression cannot have a capture-default
   75 | auto Y=[&](auto f){return[&](auto... args){return f(f, args...);};};
      |         ^
a.cc:81:19: warning: use of 'auto' in parameter declaration only available with '-std=c++20' or '-fconcepts'
   81 | inline bool chmin(auto& s,const auto& t){bool res=s>t;s=min(s,t);return res;}
      |                   ^~~~
a.cc:81:33: warning: use of 'auto' in parameter declaration only available with '-std=c++20' or '-fconcepts'
   81 | inline bool chmin(auto& s,const auto& t){bool res=s>t;s=min(s,t);return res;}
      |                                 ^~~~
a.cc:82:19: warning: use of 'auto' in parameter declaration only available with '-std=c++20' or '-fconcepts'
   82 | inline bool chmax(auto& s,const auto& t){bool res=s<t;s=max(s,t);return res;}
      |                   ^~~~
a.cc:82:33: warning: use of 'auto' in parameter declaration only available with '-std=c++20' or '-fconcepts'
   82 | inline bool chmax(auto& s,const auto& t){bool res=s<t;s=max(s,t);return res;}
      |                                 ^~~~