Where's That Fuel?

    1#include <bits/stdc++.h>
    2using namespace std;
    3using ll = long long;
    4const int inf = 1e9;
    5const long long INF = 1e17; //❄️
    6int main() {
    7    ios::sync_with_stdio(0); cin.tie(0); 
    8    int n, pos; cin >> n >> pos;
    9    vector<pair<int, int>> a;
    10    int cur = 0;
    11    for (int i = 0; i < n; i++) {
    12        int get, cost; cin >> get >> cost;
    13        if (i + 1 == pos) {
    14            cur = get;
    15            continue;
    16        }
    17        if (get - cost < 0) continue;
    18        a.emplace_back(cost, get);
    19    }
    20    sort(a.begin(), a.end(), [&] (const pair<int, int> &x, const pair<int, int> &y) {
    21            if (x.first != y.first) return x.first < y.first;
    22            return x.second > y.second;
    23    });
    24    int cnt = 1;
    25    for (int i = 0; i < a.size(); i++) {
    26        if (cur >= a[i].first) {
    27            cur -= a[i].first;
    28            cur += a[i].second;
    29            cnt++;
    30        } else {
    31            break;
    32        }
    33    }
    34    cout << cur << '\n';
    35    cout << cnt << '\n';
    36    return 0;
    37}