跪求神犇差错

对拍机n<40000,m<40000跑了2h跑不出来错误555~ 感觉自己没救了...

/*
题号：1314
题名：聪明的质监员 
作者：sgc
难度：提高+/省选- 
*/
#include<bits/stdc++.h>
using namespace std;
int x[200010];
int v[200010];
int beg[200010];
int endss[200010];
long long pre_jz[200010];
long long pre_sl[200010];
long long ans=2147483467;
long long s,UKE;
int n,m;
long long thi=0;
void print()
{
    for(int i=1;i<=n;i++)
        cout<<pre_jz[i]<<" ";
    cout<<endl;
    for(int i=1;i<=n;i++)
        cout<<pre_sl[i]<<" ";
    cout<<endl;
    system("pause");
}
bool pd(long long w)
{
    memset(pre_sl,0,sizeof(pre_sl));
    memset(pre_jz,0,sizeof(pre_jz));
    for(int i=1;i<=n;i++)
        if(x[i]>=w) 
            {
                pre_jz[i]=v[i]+pre_jz[i-1];
                pre_sl[i]=pre_sl[i-1]+1;
            }
        else
            {
                pre_jz[i]=pre_jz[i-1];
                pre_sl[i]=pre_sl[i-1];
            }
//  print();
    UKE=0,thi=0;
    for(int i=1;i<=m;i++)
        {
            UKE+=(pre_jz[endss[i]]-pre_jz[beg[i]-1])*(pre_sl[endss[i]]-pre_sl[beg[i]-1]);
        }
//  cout<<UKE<<endl;
    thi=llabs(UKE-s);
    if(UKE>s) return 1;
    else return 0;
}
int main()
{
    scanf("%d%d%d",&n,&m,&s);
    int mx=-20320,ml=2147483647;
    for(int i=1;i<=n;i++) 
        {
            scanf("%d%d",x+i,v+i);
            mx=max(mx,x[i]);
            ml=min(ml,x[i]);
        }                   
    for(int i=1;i<=m;i++) 
        {
            scanf("%d%d",beg+i,endss+i);
        }
//      cout<<mx<<ml<<endl;
    int left=ml-1,right=mx+2;
    while(left<=right)
    {
        int mid=(left+right)>>1;
        if(pd(mid))  left=mid+1;
        else right=mid-1;
        if(thi<ans) ans=thi;
    }
    cout<<ans<<endl;
    return 0;
}