Seeking the highest number of sub-strings and string appearing occurrences

Subject description:

The largest number of occurrences of substrings request string appears.
Such as string abcbcbcabc, largest number of occurrences substring is bc, occurrences 4

Idea: using the suffix array:

abcbcbcabc 0th
bcbcbcabc 1st
cbcbcabc second
bcbcabc third
cbcabc fourth
bcabc fifth
cabc sixth
abc seventh
bc 8th
c 9th

Process: Remove the start of the array 0 a, b, and then comparing the first array, found unequal, then take ab, abc, abcb .... After taking this trip, and from a first suffix array He began to take, take b, bc, bcb, bcbc ...

#include<iostream>
#include<string>
#include<vector>

using namespace std;

pair<int, string> fun(const string &str)
{
    vector<string> substrs;
    int len = str.length();

    string substring;
    int maxcount(0);
    //后缀数组
    cout << "the string is:" << str << endl;
    cout << "the substrings are as follows:" << endl;
    for (int i = 0; i < len; ++i)
    {
        substrs.push_back(str.substr(i));
        cout << substrs[i] << endl;
    }

    cout << "--------------the answer------------" << endl;

    for (int i = 0; i < len; ++i)
    {
        for (int j = 1; j <= len; j++) {
            int count = 1;
            int sublen = j;
            for (int k = i + 1; k < len; k++) {
                
                if (substrs[k].length() < sublen) {
                    break;
                }
                //cout << substrs[i].substr(0, sublen) << endl;
                //cout << substrs[k].substr(0, sublen) << endl;
                string str1 = substrs[i].substr(0, sublen);
                string str2 = substrs[k].substr(0, sublen);
                //cout << "比较结果：" << str1.compare(str2) << endl;
                //cout << "i = " << i << "  sublen = " << j << "  k = " << k << endl;
                if (str1.compare(str2)==0)
                {
                    ++count;
                }
                //cout << "count = " << count << endl;
            }
            if (count > maxcount||(count == maxcount && sublen > substring.length()))
            {
                maxcount = count;
                substring = substrs[i].substr(0, sublen);
            }
        }
    }

    return make_pair(maxcount, substring);

}


int main()
{
    string str = "ababcababcabcab";
    auto res = fun(str);

    cout << "the max count is:" << res.first << endl;
    cout << "the matched substring is:" << res.second << endl;
    return 0;
}

Output:

the string is:ababcababcabcab
the substrings are as follows:
ababcababcabcab
babcababcabcab
abcababcabcab
bcababcabcab
cababcabcab
ababcabcab
babcabcab
abcabcab
bcabcab
cabcab
abcab
bcab
cab
ab
b
--------------the answer------------
the max count is:6
the matched substring is:ab

References:

[1] a string seeking the largest number of consecutive substring https://blog.csdn.net/qq_22080999/article/details/81143555
[2] [Title] Algorithm brush up to the number of times a string of consecutive sub string https://blog.csdn.net/Neo_dot/article/details/80559744