牛客周赛round34

A 小红的字符串生成

#include<bits/stdc++.h>
#define endl "\n"
#define pb push_back
using namespace std;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
const int inf=INT_MAX;
const int mod=1e9+7;
const int maxn=1e5+7;

void solve()
{
    string a,b;
    cin>>a>>b;
    if(b==a)
    {
        cout<<2<<endl;
        cout<<a<<endl;
        cout<<a+a<<endl;
    }
    else
    {
        cout<<4<<endl;
        cout<<a<<endl;
        cout<<a+b<<endl;
        cout<<b+a<<endl;
        cout<<b<<endl;
    }
}

signed main()
{   
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    solve();
    return 0;
}

B 小红的非排列构造

#include<bits/stdc++.h>
#define endl "\n"
#define pb push_back
using namespace std;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
const int inf=INT_MAX;
const int mod=1e9+7;
const int maxn=1e5+7;

void solve()
{
    map<ll,int> mp;
    int n;
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        ll a;
        cin>>a;
        if(a>n){cout<<0<<endl;return;}
        mp[a]++;
        if(mp[a]>1)