C++ 统计自然数出现次数并排序输出

#include #include

using namespace std;

int main() { int n; cin >> n;

map<int, int> countMap;
for (int i = 0; i < n; i++) {
    int num;
    cin >> num;
    countMap[num]++;
}

vector<pair<int, int>> countVec;
for (auto it = countMap.begin(); it != countMap.end(); it++) {
    countVec.push_back(make_pair(it->first, it->second));
}

for (int i = 0; i < countVec.size(); i++) {
    cout << countVec[i].first << ' ' << countVec[i].second << endl;
}

return 0;

}