Codeforces Problem - Lala Land and Apple Trees (https://codeforces.com/contest/558/problem/A)

Lala Land and Apple Trees.cpp

#include <iostream>
#include <vector>

using namespace std;

int main() {
    int N;
    cin >> N;

    vector<pair<int, int> > ps;
    vector<pair<int, int> > ns;

    int nnegs = 0;
    int nposs = 0;

    for (int i = 0; i < N; i ++) {
        int first, second;
        cin >> first >> second;

        if (first > 0) {
            ps.push_back( make_pair(first, second));
            nposs++;
        } else {
            ns.push_back( make_pair(first, second));
            nnegs++;
        }
    }

    sort(ps.begin(), ps.end(), [] (const pair<int, int> &p1, const pair<int, int> &p2) {return p1.first < p2.first;});
    sort(ns.begin(), ns.end(), [] (const pair<int, int> &p1, const pair<int, int> &p2) {return p1.first > p2.first;});

    int ans = 0;
    int i;
    for (i =0; i < min(nposs, nnegs); i ++) {
        ans += ps[i].second;
        ans += ns[i].second;
    }
    if (nnegs!=nposs) {
        if (nposs > nnegs) {
            ans+=ps[i].second;
        } else {
            ans+=ns[i].second;
        }
    }

    cout << ans << endl;
    return 0;
}