去掉字符串中連續出現K個0的子串

#include <iostream>
#include <string>
using namespace std;
string removeK(string str, int k)
{
    if(k < 1)
        return str;
    int count = 0;
    int start = -1;
    for(int i = 0; i < str.size(); ++i)
        if(str[i] == '0')
        {
            ++count;
            start = start == -1 ? i : start;
        } else {
            if(count == k)
                str.erase(str.begin() + start, str.begin() + start + count);
            count = 0;
            start = -1;
        }
       if(count == k)
                str.erase(str.begin() + start, str.begin() + start + count);
        return str;
}
int main()
{
    string str = "A00B000";
    cout << removeK(str, 2) << endl;
}