2Puq38 - Online C++0x Compiler & Debugging Tool

#include <iostream>
#include <vector>
#include <unordered_map>
#include <algorithm>

using namespace std;

pair<vector<long long >,long long > findZeroSumSubarrayWithMostRepeatedElement(vector<long long >& arr) {
    unordered_map<long long , long long > prefixSumMap;
    unordered_map<long long , long long > frequencyMap;
    long long  maxFreq = 0, mostRepeatedElement = arr[0];
    long long  start = -1, end = -1;
    long long  prefixSum = 0;

    prefixSumMap[0] = -1;

    for (long long  i = 0; i < arr.size(); i++) {
        prefixSum += arr[i];

        if (prefixSumMap.find(prefixSum) != prefixSumMap.end()) {
            long long leftIndex = prefixSumMap[prefixSum] + 1;
            vector<long long> subarray(arr.begin() + leftIndex, arr.begin() + i + 1);


            unordered_map<long long, long long> tempFreq;
            for (long long num : subarray) tempFreq[num]++;


            for (auto& [num, freq] : tempFreq) {
                if (freq > maxFreq) {
                    maxFreq = freq;
                    mostRepeatedElement = num;
                    start = leftIndex;
                    end = i;
                }
            }
        } else {
            prefixSumMap[prefixSum] = i;
        }
    }

    vector<long long> bestSubarray;
    if (start != -1) {
        bestSubarray.assign(arr.begin() + start, arr.begin() + end + 1);
    }

    return {bestSubarray, mostRepeatedElement};
}

int main() {
    vector<long long> niz;
    long long n;
    cin >> n;
    for (long long i = 0; i < n; i++){
    	long long temp;
    	cin >> temp;
    	niz.push_back(temp);
    }

    auto [subarray, mostFrequent] = findZeroSumSubarrayWithMostRepeatedElement(niz);

    long long brojac = 0;

    for (long long num : subarray)
    	if(num == mostFrequent)
    		brojac++;
    cout << "\nMost Repeated Element: " << mostFrequent << endl;

    return 0;
}