离散化

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
const int N = 300000;
int a[N],s[N];
typedef pair<int, int> PII;
vector<int> alls;
vector<PII> add,query;
int find(int x)
{
    int l = 0, r = alls.size()-1;
    while(l<r)
    {
        int mid = l + r >> 1;
        if(alls[mid] >= x) r = mid;
        else l = mid + 1;
    }
    return r + 1;
}
int main()
{
    int n,m;
    cin>>n>>m;
    while(n--)
    {
        int x,c;
        cin>>x>>c;
        alls.push_back(x);
        add.push_back({x,c});
    }
    while(m--)
    {
        int l,r;
        cin>>l>>r;
        alls.push_back(l);
        alls.push_back(r);
        query.push_back({l,r});
    }
    sort(alls.begin(), alls.end());
    alls.erase(unique(alls.begin(), alls.end()), alls.end());
    
    for(auto item : add)
    {
        int x = find(item.first);
        a[x] += item.second;
    }
    for(int i = 1;i<=alls.size();i++) s[i] = s[i-1] + a[i];
    for(auto item : query)
    {
        int l = find(item.first), r = find(item.second);
        cout<<s[r] - s[l-1]<<endl;
    }
}