n = int(input())
for j in range(0,n):
m = int(input())
a = input().split()
l =[]
p =[]
for o in range(0,m):
if int(a[o]) not in l:
l.append(int(a[o]))
else:
p.append(int(a[o]))
b = False
for i in range(0, len(l)):
if i not in l:
b = True
break
if b:
s = (i)
else:
s = (len(l))
if p == []:
print(s)
else:
b = False
for i in range(0, len(p)):
if i not in p:
b = True
break
if b:
print(s+i)
else:
print(s+len(p))
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define mod 1000000007
#define pb push_back
int main (){
int t;
cin>>t;
while(t--){
int n;
cin>>n;
vector<int>a(n);
for(int i=0;i<n;i++) cin>>a[i];
sort(a.begin(),a.end());
if(a[0]!=0){
cout<<0<<endl;
continue;
}
int missing;
for(int i=0;i<=100;i++){ if(find(a.begin(),a.end(),i)==a.end()){ missing=i;break;}}
int ans;
int j=0;
for(;j<n;j++){
if(j==0 && a[j]!=a[j+1]){ ans=a[0];
break;
}
else if(j==n-1 && a[j]!=a[j-1]) {
ans=a[n-1];
break;
}
else if(a[j-1]!=a[j] && a[j]!=a[j+1]) {
ans=a[j];
break;
}
}
if(j==n) ans=a[n-1]+1;
if(ans>missing) cout<<2*missing<<endl;
else cout<<missing+ans<<endl;
}
return 0;
}380. Insert Delete GetRandom O(1) | 332. Reconstruct Itinerary |
368. Largest Divisible Subset | 377. Combination Sum IV |
322. Coin Change | 307. Range Sum Query - Mutable |
287. Find the Duplicate Number | 279. Perfect Squares |
275. H-Index II | 274. H-Index |
260. Single Number III | 240. Search a 2D Matrix II |
238. Product of Array Except Self | 229. Majority Element II |
222. Count Complete Tree Nodes | 215. Kth Largest Element in an Array |
198. House Robber | 153. Find Minimum in Rotated Sorted Array |
150. Evaluate Reverse Polish Notation | 144. Binary Tree Preorder Traversal |
137. Single Number II | 130. Surrounded Regions |
129. Sum Root to Leaf Numbers | 120. Triangle |
102. Binary Tree Level Order Traversal | 96. Unique Binary Search Trees |
75. Sort Colors | 74. Search a 2D Matrix |
71. Simplify Path | 62. Unique Paths |