def sol():
n=int(input())
for i in range(n):
m=int(input())
l1=[]
l=list(map(int,input().split(" ")))
if m==1 or m==0:
print("YES")
continue
g4=0
g3=0
g2=0
for j in range(0,m-1):
if l[j+1]-l[j]==3:
g3+=1
continue
elif l[j+1]-l[j]==2:
g2+=1
continue
elif l[j+1]-l[j]>=4:
g4+=1
if (g4>0):
print("NO")
elif (g3<=1 and g2==0):
print("YES")
elif(g3==0 and g2<=2):
print("YES")
else:
print("NO")
sol()
#include <bits/stdc++.h>
#define int long long int
#define fastio \
ios_base::sync_with_stdio(false); \
cin.tie(NULL)
#define endl "\n"
using namespace std;
void solve(){
int n;
cin>>n;
vector<int>v(n);
bool l=true;
bool r=true;
for(auto &i : v)cin>>i;
for(int i=0;i<n-1;i++){
if(l)v[i]++;
else l=true;
if(v[i+1]-v[i]>1){v[i+1]--;l=false;}
else if(v[i+1]-v[i]==1){l=false;}
}
if(l==true and v[n-1]-v[n-2]==0)v[n-1]++;
// for(auto i : v){
// cout<<i<<" ";
// }
// cout<<endl;
for(int i=0;i<n-1;i++){
if(v[i+1]-v[i]>=2){
cout<<"NO"<<endl;return;
}
}
cout<<"YES"<<endl;
}
signed main()
{
fastio;
int t;
cin>>t;
while(t--){
solve();
}
return 0;
}
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