二分,map,前缀和

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <map>

using namespace std;

const int N = 100010;
typedef pair<int, int> PII;
PII points[N];
map<int, int> mp;
int s[N];

bool cmp(PII x, PII y){
    return x.first < y.first;
}

int main()
{
    int n, m;
    cin >> n >> m;

    for(int i = 1;i <= n;i ++ ){
        int x, c;
        cin >> x >> c;
        mp[x] += c;
    }

    int cnt = 0;
    for(auto x : mp) points[++ cnt] = {x.first, x.second};
    for(int i = 1;i <= n;i ++ ) s[i] = s[i - 1] + points[i].second;
    sort(points + 1, points + cnt + 1, cmp);

    while(m --){
        int l, r;
        cin >> l >> r;

        //找到第一个大于等于 l 的
        int ansL = 0, ansR = 0;
        int L = 1, R = cnt;
        while(L < R){
            int mid = L + R >> 1;
            if(points[mid].first < l) L = mid + 1;
            else R = mid;
        }
        if(points[L].first < l){
            printf("%d\n",0);
            continue;
        }else{
            ansL = L;
        }
        //找到最后一个小等于等 r 的
        L = 1, R = cnt;
        while(L < R){
            int mid = L + R + 1 >> 1;
            if(points[mid].first > r) R = mid - 1;
            else L = mid;
        }
        if(points[L].first > r){
            printf("%d\n",0);
            continue;
        }else{
            ansR = R;
        }

        cout << s[ansR] - s[ansL - 1] << endl;
    }

    return 0;
}