#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/tree_policy.hpp>
#define INF 1e9
#define INFl 1e18
#define all(x) x.begin(), x.end()
#define sajz(x) (int)x.size()
#define pb push_back
#define s second
#define f first
#define yes puts("YES")
#define no puts("NO")
#define erase_duplicates(x) {sort(all(x));(x).resize(distance((x).begin(), unique(all(x))));}
using namespace std;
//using namespace __gnu_pbds;
void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifndef ONLINE_JUDGE
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif

#define int ll

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef set<int> si;
typedef multiset<int> msi;
typedef long double ld;
//typedef cc_hash_table<int, int, hash<int>> ht;

array<vi, 2> manacher(const string& s) {
    int n = sajz(s);
    array<vi,2> p = {vi(n+1), vi(n)};
    for (int z = 0; z <= 1; z ++) for (int i=0,l=0,r=0; i < n; i++) {
        int t = r-i+!z;
        if (i<r) p[z][i] = min(t, p[z][l+t]);
        int L = i-p[z][i], R = i+p[z][i]-!z;
        while (L>=1 && R+1<n && s[L-1] == s[R+1])
            p[z][i]++, L--, R++;
        if (R>r) l=L, r=R;
    }
    return p;
}

bool check(string &s, vi &a) {
    array<vi, 2> p = manacher(s);

    for (int i = 0; i < sajz(a); i ++) {
        if (p[1][i] != a[i]) return false;
    }
    return true;
}

void test_case() {
    int n;
    cin >> n;

    vi a(n);
    for (int i = 0; i < n; i ++) cin >> a[i];

    string s1 = "00";
    for (int i = 2; i < n; i ++) {
        if (a[i-1] == 0) {
            if (s1[i-2] == '0') s1 += "1";
            else s1 += "0";
        } else {
            s1 += s1[i-2];
        }
    }
    string s2 = "01";
    for (int i = 2; i < n; i ++) {
        if (a[i-1] == 0) {
            if (s2[i-2] == '0') s2 += "1";
            else s2 += "0";
        } else {
            s2 += s2[i-2];
        }
    }
    string s3 = "10";
    for (int i = 2; i < n; i ++) {
        if (a[i-1] == 0) {
            if (s3[i-2] == '0') s3 += "1";
            else s3 += "0";
        } else {
            s3 += s3[i-2];
        }
    }
    string s4 = "11";
    for (int i = 2; i < n; i ++) {
        if (a[i-1] == 0) {
            if (s4[i-2] == '0') s4 += "1";
            else s4 += "0";
        } else {
            s4 += s4[i-2];
        }
    }

    vector<string> ans;
    if (check(s1, a)) ans.pb(s1);
    if (check(s2, a)) ans.pb(s2);
    if (check(s3, a)) ans.pb(s3);
    if (check(s4, a)) ans.pb(s4);

    cout << sajz(ans) << '\n';
    for (auto it : ans) cout << it << '\n';
}

int32_t main() {
    ios_base::sync_with_stdio(false);
    cout.tie(0);
    cin.tie(0);

    int t=1;
    cin >> t;
    while(t--)test_case();

    return 0;
}