两个字符串的相同字串个数

#include<iostream>
#include <set>
#include <climits>
#include <cstring>
using namespace std;
bool isSubString(string subString, string str)
{
    int subLength = subString.length();
    int strLength = str.length();
    if(subLength == 0)
    {
        return false;
    }

    for(int i = 0;i < strLength - subLength;++i)
    {
        string sunStringTemp = str.substr(i, subLength);
        if(sunStringTemp == subString)
        {
            return true;
        }
    }
    return false;
}

int main()
{
    int counter = 0;
    set<string> vec;
    string str1, str2;
    cin >> str1 >> str2;
    int lengthStr1 = str1.length();
    int lengthStr2 = str2.length();
    for(int i = 0;i < lengthStr1;++i)
    {
        for(int j = 0;j <= lengthStr1 - i;++j)
        {
            string subString = str1.substr(i, j);
            if(isSubString(subString, str2) && (vec.find(subString)==vec.end()))
            {
                vec.insert(subString);
                cout << subString << " ";
                counter++;
            }
        }
    }
    cout << endl << counter;

    return 0;
}