c++ 문자열 정해진 길이로 쪼갠 후 갯수 새기

source.cpp

#include <iostream>
#include <string>
#include <map>

using namespace std;

int main(void) {   
    int wordLength;
    string source;
    map<string, int> dictionary;
    cin >> wordLength;    
    cin >> source;
    for (auto i = 0; i < source.length(); i += wordLength) {
        dictionary[source.substr(i, wordLength)]++;
    }
    string greatest;
    int seed = 0;
    for (auto& x : dictionary) {
        if (x.second > seed) {
            greatest = x.first;
            seed = x.second;
        }
    }
    cout << greatest << endl;
    return 0;
}