请dalao瞅一眼问题在哪，好像有的NO没判出来

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define re register
#define INF 0x3f3f3f3f
#define il inline
#define pb push_back
#define ft first
#define sd second
#define mp make_pair
#define INF 0x3f3f3f3f
#define pb push_back
#define P pair<int,int>
//#define cin fin
//#define cout fout
//ifstream cin("文件名.in");
//ofstream cout("文件名.out");
const int MAXN = 2e5;
int las[MAXN + 5], pre[MAXN + 5], a[MAXN + 5];
vector<int> v[MAXN + 5];
bool sha[MAXN + 5];
int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int t;
	cin >> t;
	for(int o = 0; o < t; ++o){
		int n;
		cin >> n;
		int cnt0 = 0;
		bool flag = 0;
		for(int i = 1; i <= n; ++i){
			pre[i] = i + 1;
			las[i] = i - 1;
			cin >> a[i];
			if(a[i] == 0)cnt0++; 
			v[a[i]].pb(i);
		}
		if(cnt0 != 1){
			cout << "NO" << endl;
			for(int i = n - 1; i >= 0; --i)v[i].clear();
			continue;
		}
		for(int i = n - 1; i >= 1; --i){
			for(int j = 0; j < (int)v[i].size(); ++j){
				int last = las[v[i][j]], pren = pre[v[i][j]];
				if((last != 0 && a[last]==  i - 1 ) || (pren != n + 1 && a[pren] == i - 1)){
					pre[last] = pren;	
					las[pren] = last;
					
					sha[v[i][j]] = 1;
				}
				else if(v[i][j] == n || a[pren] != i){
					flag = 1;
					break;
				}
			}
			if(flag){
				break;
			}
			for(int j = 0; j < (int)v[i].size(); ++j){
				if(!sha[v[i][j]]){
					int last = las[v[i][j]], pren = pre[v[i][j]];
					pre[last] = pren;
					las[pren] = last;
					
					sha[v[i][j]] = 1;
				}
			} 
		}
		if(!flag){
			for(int i = 1; i <= n; ++i){
				if(a[i] != 0 && !sha[i]){
					flag = 1;
					break;
				}
			}
		}
		if(flag)cout << "NO" << endl;
		else cout <<"YES"<<endl;
		for(int i = 1; i <= n; ++i)sha[i] = 0;
		for(int i = n - 1; i >= 0; --i)v[i].clear();
	} 
	return 0;
}