STL_<set>

DESCRIPTION OF THE PRIOR a set of integers (allowing duplicate elements), initially empty. We define as follows:
the Add x x added to collection
del set x to x equal to all the element deletion
ASK x in a case where the collection element x interrogation
of each operation, we require the following output.
set x add output operation after the number of
the number x set before the output operation del
ask first output indicating whether 0 or 1 was added to the set of x (0 indicates never added), and then outputs the number of the current set of x, intermediate opening by spaces. The first input line is an integer n, the number of commands. 0 <= n <= 100000.
N back line commands, as described in the Description. Total n output lines, each output line required.

Sample input

7
add 1
add 1
ask 1
ask 2
del 2
del 1
ask 1

Sample Output

1
2
1 2
0 0
0
2
1 0

---

#include <iostream>
#include <set>
using namespace std;

int main()
{
    multiset<int>a;
    set<int>v;
    char s[5];
    int n, p;
    multiset<int>::iterator m;
    cin >> n;
    for (int i = 0; i < n; ++i) {
        cin >> s >> p;
        switch (s[1]) {
        case 'd':
            a.insert(p);
            v.insert(p);
            cout << a.count(p) << endl;
            break;
        case 'e':
            cout << a.count(p) << endl;
            m = a.find(p);
            while (m != a.end()) {
                a.erase(m);
                m = a.find(p);
            }
            break;
        case 's':
            if (v.find(p) == v.end())cout << 0;
            else cout << 1;
            cout << ' ' << a.count(p) << endl;
            break;
        }
    }

    return 0;
}