做法：二分加前缀和。

#include <bits/stdc++.h>
#define ll long long
using namespace std;
ll n,m,s,w[200010],v[200010],sumw[200010],sumv[200010],r[200010],l[200010];
ll minn=1e18,maxn=-1e18;
ll ans=1e18,sum;
bool check(int wans){
	sum=0;
	memset(sumw,0,sizeof(sumw));
	memset(sumv,0,sizeof(sumv));
	for(int i=1;i<=n;i++){
		if(w[i]>=wans){
			sumw[i]=sumw[i-1]+1;
			sumv[i]=sumv[i-1]+v[i];
		}
		else{
			sumw[i]=sumw[i-1];
			sumv[i]=sumv[i-1];
		}
	}
	for(int i=1;i<=m;i++){
		sum+=(sumw[r[i]]-sumw[l[i]-1])*(sumv[r[i]]-sumv[l[i]-1]);
	}
	sum=llabs(sum-s);
	if(sum>s){
		return true;
	}
	return false;
}
int main(){
	cin>>n>>m>>s;
	for(int i=1;i<=n;i++){
		cin>>w[i]>>v[i];
		minn=min(minn,w[i]);
		maxn=max(maxn,w[i]);
	}
	for(int i=1;i<=m;i++){
		cin>>l[i]>>r[i];
	}
	int l1=minn-1,r1=maxn+2;
	while(l1!=r1){
		int mid=(l1+r1)/2;
		if(check(mid)){
			l1=mid+1;
		}
		else{
			r1=mid;
		}
		ans=min(sum,ans);
	}
	cout<<ans<<endl;
	return 0;
}

蒟蒻代码调试能力太差了，求调QAQ