#include<iostream>
#include<list>

using namespace std;

int main() {
    list<int> l;
    int n = 100;
    for(int i = 0; i < n; i++) {
        l.push_back(i);
    }
    list<int>::iterator it = l.end();
    it--;
    for(; !l.empty(); it--) {
        cout << "the size of l is " << (int) l.size() << endl;
        l.erase(it);
    }
}

#include<iostream>
#include<list>

using namespace std;

int main() {
    list<int> l;
    int n = 100;
    for(int i = 0; i < n; i++) {
        l.push_back(i);
    }
    list<int>::iterator it = l.end();
    it--;
    for(; !l.empty();) {
        cout << "the size of l is " << (int) l.size() << endl;
        l.erase(it--);
    }
}