二分，注意一下怎么确定数据范围，使用long long
Y随W增大而减小，具有单调性
#include<bits/stdc++.h>
using namespace std;
const int N = 200010;
typedef long long LL;
int w[N], v[N], L[N], R[N];
LL sum[N], cnt[N];
int n, m;
LL S;
LL get_y(int W) {
LL res = 0;
for (int i = 1; i <= n; i++) {
if (w[i] >= W) {
sum[i] = sum[i - 1] + v[i];
cnt[i] = cnt[i - 1] + 1;
} else {
sum[i] = sum[i - 1];
cnt[i] = cnt[i - 1];
}
}
for (int i = 1; i <= m; i++) {
res += (sum[R[i]] - sum[L[i] - 1]) * (cnt[R[i]] - cnt[L[i] - 1]);
}
return res;
}
int main() {
ios::sync_with_stdio(0);
cin >> n >> m >> S;
for (int i = 1; i <= n; i++)cin >> w[i] >> v[i];
for (int i = 1; i <= m; i++)cin >> L[i] >> R[i];
int l = 0, r = 1e6+10;
while (l < r) {
int mid = (l + r + 1) >> 1;
LL Y = get_y(mid);
if (Y >= S)l = mid;
else r = mid - 1;
}
cout << min(get_y(r) - S, S- get_y(r + 1));
}
