How to get the least number after deleting k digits from the input number

Question

For example, if the input number is 24635, the least number is 23 after deleting any 3 digits.

It\'s not the same as taking the two smalles

Answer 1

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#define mod 1000000007
#define ll long long
using namespace std;
bool Compare (pair p1, pair p2)  {
    if (p1.first < p2.first) {
        return true;
    }
    return false;
}
int main() {
    priority_queue , vector  >, function, pair ) > > pq (Compare);
    int n, k;
    cin>>n>>k;
    int i = 1;
    while (n) {
        pq.push(make_pair(n%10, i));
        n = n/10;
        i++;
    }
    for(int j =1; j<=k;j++){
        pq.pop();
    }
    int number = pq.top().first;
    int index = pq.top().second;
    int digit = 1;
    pq.pop();
    while(!pq.empty()){
        int current_index = pq.top().second;
        digit = digit * 10;
        if(current_index < index) {
            number = number * 10 + pq.top().first;
        } else {
            number = digit * pq.top().first + number;
        }
        pq.pop();
    }
    cout<

I solved the question using priority_queue with pair. please let me know if there is any better solution