PTA 7-1 删除字符串中的子串 (20分)

#include 
#include 

using namespace std;

int main()
{
    string s1, s2;
    getline(cin, s1);
    getline(cin, s2);
    int index = s1.find(s2);
    while(index >= 0)
    {
        s1.erase(index, s2.length());
        index = s1.find(s2);
    }
    cout<<s1<<endl;
}