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;
}2144. Minimum Cost of Buying Candies With Discount | Non empty subsets |
1630A - And Matching | 1630B - Range and Partition |
1630C - Paint the Middle | 1630D - Flipping Range |
1328A - Divisibility Problem | 339A - Helpful Maths |
4A - Watermelon | 476A - Dreamoon and Stairs |
1409A - Yet Another Two Integers Problem | 977A - Wrong Subtraction |
263A - Beautiful Matrix | 180C - Letter |
151A - Soft Drinking | 1352A - Sum of Round Numbers |
281A - Word Capitalization | 1646A - Square Counting |
266A - Stones on the Table | 61A - Ultra-Fast Mathematician |
148A - Insomnia cure | 1650A - Deletions of Two Adjacent Letters |
1512A - Spy Detected | 282A - Bit++ |
69A - Young Physicist | 1651A - Playoff |
734A - Anton and Danik | 1300B - Assigning to Classes |
1647A - Madoka and Math Dad | 710A - King Moves |