1781 컵라면

#include <stdio.h>
#include <vector>
#include <utility>
#include <algorithm>
#include <queue>
 
using namespace std;
 
vector<pair<int, int> > arr;
 
bool compare(pair<int, int> a, pair<int, int> b) {
    if (a.first == b.first) {
        return a.second > b.second;
    }
    else if (a.first > b.first) {
        return true;
    }
    else {
        return false;
    }
}
 
int main() {
    int n, line = 0;
    scanf("%d", &n);
 
    for (int i = 0; i < n; i++) {
        int dead, v;
        scanf("%d %d", &dead, &v);
 
        arr.push_back(make_pair(dead, v));
 
        if (line < dead)
            line = dead;
    }
 
    sort(arr.begin(), arr.end(), compare);
    
    long long sum = 0;
    priority_queue<int> pq;
    for (int i = line, j = 0; i >= 1; i--) {
        for (; j < n && arr[j].first >= i;) {
            pq.push(arr[j].second);
            j++;
        }
 
        if (pq.empty() != true) {
            sum += pq.top();
            pq.pop();
        }
    }
 
    printf("%lld", sum);
}