NOIP1138 聪明的质监员

#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<cmath>
#include<algorithm>
using namespace std;
const int maxn = 220005;
struct STONE{
    long long w;
    long long v;
};
long long n,m,s,l[maxn],r[maxn],sum[maxn],sumv[maxn],all,ans = 98765432112345L;
STONE stone[maxn];
void input(){
    cin>>n>>m>>s;
    all = 0;
    for(int i = 1;i <= n;i++){
        scanf("%lld%lld",&stone[i].w,&stone[i].v);
        if(all < stone[i].w) all = stone[i].w;
    }
    for(int i = 1;i <= m;i++){
        scanf("%lld%lld",&l[i],&r[i]);
    }
}
bool check(long long t){
    sum[0] = sumv[0] = 0;
    for(int i = 1;i <= n;i++){
            if(stone[i].w >= t){
                sumv[i] = sumv[i-1] + stone[i].v;
                sum[i] = sum[i-1] + 1;
            }else{
                sumv[i] = sumv[i-1];
                sum[i] = sum[i-1];
            }
    }
    all = 0;
    for(int i = 1;i <= m;i++){
        all += (sumv[r[i]] - sumv[l[i]-1]) * (sum[r[i]] - sum[l[i]-1]);
    }
    ans = min(abs(all - s),ans);
    return all < s;
}
void div(){
    long long lans = 0,rans = all,mans;
    while(lans <= rans){
        mans = (lans + rans) >> 1;
        if(check(mans)){
            rans = mans - 1;
        }else{
            lans = mans + 1;
        }
    }
    check(mans+1);
    if(mans > 0)check(mans-1);
    cout<<ans;
}
int main(){
    input();
    div();
    return 0;
}