HackerRank Vector Erase Problem in C++

VectorErase.cpp

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    vector<int> ins;
    int n, erSingle, erRangeS, erRangeE;
    cin>>n;
    while(n){
        int val;
        cin>>val;
        ins.push_back(val);
        n--;
    }
    cin>>erSingle;
    ins.erase(ins.begin()+(erSingle-1));
    cin >> erRangeS >> erRangeE;
    ins.erase(ins.begin()+erRangeS-1, ins.begin()+erRangeE-1);
    cout<<ins.size()<<endl;
    for(int i = 0; i<ins.size(); i++){
        cout<<ins[i]<<" ";
    }
    return 0;
}