#include <bits/stdc++.h>

using namespace std;

class Solution {

public:

// optimal

int secondHighestOccurringElement(vector<int>& nums) {

int maxEle = -1;

int secondMaxEle = -1;

int maxFreq = 0;

int secondMaxFreq = 0;

// using unordered map to store element and frequency

unordered_map<int, int> umap;

// add values to map

for (int i=0; i<nums.size(); i++) {

umap[nums[i]]++;

}

for (auto it : umap) {

int ele = it.first;

int freq = it.second;

// check if freq is maxFreq

if (freq > maxFreq) {

secondMaxFreq = maxFreq;

secondMaxEle = maxEle;

maxFreq = freq;

maxEle = ele;

// if both are equal, check which is the min element and replace

} else if (freq == maxFreq) {

maxEle = min(ele, maxEle);

}

// check if freq is secondMaxFreq

else if (freq > secondMaxFreq) {

secondMaxFreq = freq;

secondMaxEle = ele;

// if both are equal, replace

} else if (freq == secondMaxFreq) {

secondMaxEle = min(ele, secondMaxEle);

}

}

return secondMaxEle;

}

// bruteforce

int func(int arr[], int size) {

int visited[1000 + 1] = {0};

int maxFreq = 0;

int secondMaxFreq = 0;

int maxEle = -1;

int secondMaxEle = -1;

for (int i=0; i<size; i++) {

if (visited[arr[i]] == 0) {

int count = 0;

for (int j=0; j<size; j++) {

if (arr[i] == arr[j]) {

visited[arr[i]] = 1;

count++;

}

}

if (count > maxFreq) {

secondMaxFreq = maxFreq;

secondMaxEle = maxEle;

maxFreq = count;

maxEle = arr[i];

} else if (count == maxFreq) {

maxEle = min(arr[i], maxEle);

} else if (count > secondMaxFreq) {

secondMaxFreq = count;

secondMaxEle = arr[i];

} else if (count == secondMaxFreq) {

secondMaxEle = min(secondMaxEle, arr[i]);

}

}

}

return secondMaxEle;

}

};

int main() {

vector<int> nums = {4, 4, 5, 5, 6, 7};

Solution sol;

cout << sol.secondHighestOccurringElement(nums);

return 0;

}