如何在哈希表c++中返回出现次数？

#include <iostream>
#include <unordered_map>
using namespace std;

unordered_map<int, int> countOccurrences(const vector<int>& nums) {
    unordered_map<int, int> occurrences;
    for (int num : nums) {
        if (occurrences.count(num)) {
            occurrences[num]++;
        } else {
            occurrences[num] = 1;
        }
    }
    return occurrences;
}

int main() {
    vector<int> nums = {1, 2, 3, 2, 1, 3, 3, 4, 5, 4};
    unordered_map<int, int> occurrences = countOccurrences(nums);
    for (const auto& pair : occurrences) {
        cout << "Element: " << pair.first << ", Count: " << pair.second << endl;
    }
    return 0;
}