算法1

(set做法)

blablabla

C++ 代码

#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstring>
#include<set>
using namespace std;
const int maxn = 1000005;
int a[maxn],b[maxn];
int n,value,first,second;
set<int>sets;
set<int>::iterator it;
int main(void) {
    cin >> n;
    while(scanf("%d",&value) != EOF) {
        if(sets.find(value) != sets.end()) {
            first = value;
        } else {
            sets.insert(value);
        }
    }
    int res = 0;
    for(it = sets.begin(); it != sets.end(); it ++) {
        a[res ++] = *it;
    }
    for(int i = 1; i < res; i ++) {
        if(a[i] - a[i - 1] != 1) {
            second = a[i - 1] + 1;
            break;
        }
    }
    cout<<second<<" "<<first<<endl;
    return 0;
}