y总基于排序的做法

#include <cstring>
#include <sstream>
#include <iostream>
#include <algorithm>

using namespace std;

const int N = 1e5 + 10;

int n;
int a[N];

int main()
{
    int cnt;
    cin >> cnt;
    string line;

    getline(cin, line); //忽略第一行的空格
    while (cnt --)
    {
        getline(cin, line);
        stringstream ssin(line);

        while (ssin >> a[n]) n ++;
    }

    sort(a, a + n);

    int res1, res2;
    for (int i = 1; i < n; i ++)
    {
        if (a[i] == a[i - 1]) res2 = a[i]; //重号
        else if (a[i] >= a[i - 1] + 2) res1 = a[i] - 1; //断号
    }

    cout << res1 << " " << res2 << endl;

    return 0;
}