不习惯vector版本，贴个数组版本离散化吧

C++ 代码

#include <algorithm>
#include <iostream>
#include <cstdio>
#define fi first
#define se second
using namespace std;

typedef long long LL;
typedef pair<int,int> PII;
const int N = 1e5 + 10;
PII a[N],b[N];
LL c[3 * N];
int tot[3 * N];
int n,m;

void insert(int l, int r,int val){
    c[l] += val;
    c[r + 1] -= val;
}

int main(){
    scanf("%d%d", &n, &m);

    int cnt = 0;
    for(int i = 1;i <= n; ++ i){
        int x, c;
        scanf("%d%d", &x, &c);
        a[i] = {x, c};
        tot[++ cnt] = x;
    }

    for(int i = 1; i <= m; ++ i){
        int l, r;
        scanf("%d%d", &l, &r);
        b[i] = {l, r};
        tot[++ cnt] = l;
        tot[++ cnt] = r;
    }

    sort(tot + 1,tot + 1 + cnt);
    cnt = unique(tot + 1, tot + 1 + cnt) - tot - 1;

    for(int i = 1; i <= n; ++ i){
        a[i].fi = lower_bound(tot + 1, tot + 1 + cnt, a[i].fi) - tot;
        int x = a[i].fi;
        int y = a[i].se;
        insert(x, x, y);
    }

    for(int i = 1; i <= cnt; ++ i) c[i] += c[i-1];
    for(int i = 1; i <= cnt; ++ i) c[i] += c[i-1];

    for(int i = 1; i <= m; ++ i){
        int x = lower_bound(tot + 1, tot + 1 + cnt, b[i].fi) - tot;
        int y = lower_bound(tot + 1, tot + 1 + cnt, b[i].se) - tot;
        printf("%lld\n", c[y] - c[x - 1]);
    }
    return 0;
}