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| #include <bits/stdc++.h>
#pragma optimization_level 3
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimization ("unroll-loops")
struct PairHash {
inline std::size_t operator()(const std::pair<int, int> &v) const { return v.first * 31 + v.second; }
};
#define M_PI 3.14159265358979323846
#define MAX_N 202020
#define INF 987654321
#define EPS 1e-9
#define ll long long
#define pll pair<ll, ll>
#define vpll vector<pll>
#define vall3 vector<array<ll,3>>
#define all3 array<ll,3>
#define all5 array<ll,5>
#define vall5 vector<all5>
#define vll vector<ll>
#define vi vector<int>
#define vs vector<string>
#define usll unordered_set<ll>
#define uspll unordered_set<pll, PairHash>
#define umll unordered_map<ll,ll>
#define vvs vector<vs>
#define vvll vector<vll>
#define all(a) begin(a), end(a)
#define rall(a) rbegin(a), rend(a)
ll __gcd(ll x, ll y) { return !y ? x : __gcd(y, x % y); }
using namespace std;
ll p[] = {2,3,5,7,11,13,17,19,23,29,31};
vpll solve(vll A) {
ll n = A.size();
umll freq;
vll rma(n);
usll us;
for(ll i = n - 1, ma = 0; i >= 0; i--) {
if(++freq[A[i]] > 2) return {};
if(freq[A[i]] == 2) us.insert(A[i]);
rma[i] = ma = max(ma, A[i]);
}
freq.clear();
vpll res;
for(ll i = 0, ma = 0; i < n - 1; i++) {
if(++freq[A[i]] == 2) break;
us.erase(A[i]);
ma = max(ma, A[i]);
if(ma == i + 1 and us.empty()) {
ll l = i + 1, r = n - i - 1;
if(rma[i + 1] == r)
res.push_back({l, r});
}
}
return res;
}
int main() {
ios_base::sync_with_stdio(0);
ios::sync_with_stdio(0);
cin.tie(0);
cout.precision(12);
ll tc = 1;
cin>>tc;
for (ll i = 1; i <= tc; i++) {
ll n;
cin>>n;
vll A(n);
for(ll j = 0; j < n; j++) cin>>A[j];
auto res = solve(A);
cout<<res.size()<<endl;
for(auto& [a,b] : res) cout<<a<<' '<<b<<endl;
}
return 0;
}
|
