cpp 出现iiiizzzz原因/多出zz

#include<iostream>
#include<string>
#include<map>
using namespace std;
int main()
{
    int min = 1;
    int flag[20];
    map<char, int> mymap;
    string str;
    while (cin >> str)
    {
        mymap.clear();     //！！！！注意清空否则下一个会出错
        for (int i = 0; i < str.size(); i++)
        {

            if (mymap.count(str[i])) //存在key
            {
                mymap[str[i]]++;
            }
            else
            {
                mymap[str[i]] = 1;
            }
            if (min >= mymap[str[i]])
            {
                min = mymap[str[i]];
            }
        }
        for (int i = 0; i < str.size(); i++) //删除min代表的
        {
            if (mymap[str[i]] != min)
            {
                cout << str[i];
            }
        }
        cout<<endl;         //无此则出现iiiizzzz，多出其中zzzz，用例中并无zzzz
    }
    return 0;
}