题解 | #查找第K小数#

需要将去重复考虑进去

#include <iostream>
#include <queue>
#include <set>
using namespace std;

int main() 
{
    int N;
    while (cin >> N) {
        priority_queue<int> pq;
        vector<int> vec;
        set<int> st;
        while (N--) {
            int val;
            cin >> val;
            vec.push_back(val);
        }
        int k;
        cin >> k;
        for (int i = 0; i < vec.size(); i++) {
            if (pq.size() < k) {
                if (st.find(vec[i]) != st.end()) {
                    continue;
                }
                st.insert(vec[i]);
                pq.push(vec[i]);
            }
            else if (pq.size() == k) {
                int tmp = pq.top();
                if (vec[i] >= tmp) {
                    continue;
                }
                else {
                    if (st.find(vec[i]) != st.end()) {
                        continue;
                    }
                    st.erase(pq.top());
                    pq.pop();
                    st.insert(vec[i]);
                    pq.push(vec[i]);
                }
            }
        }
        cout << pq.top() << endl;
    }
    return 0;
}