n = int(input())
arr = list(map(int, input().split()))
arr.sort(reverse=True)
count = 0
last = 10**10
for i in range(n):
cur = arr[i]
if cur + 1 < last:
last = cur + 1
count += 1
elif cur < last:
last = cur
count += 1
elif cur - 1 != 0 and cur - 1 < last:
last = cur - 1
count += 1
print(count)// Online C++ compiler to run C++ program online
#include <bits/stdc++.h>
using namespace std;
int main() {
int n;
cin>>n;
vector<int> v(n);
for(int i=0;i<n;i++){
cin>>v[i];
}
sort(v.begin(),v.end());
unordered_set<int> s;
for(int i=0;i<n;i++){
int a=v[i];
if(a==1){
if(s.count(a)==0)
s.insert(a);
else s.insert(a+1);
}else{
if(s.count(a-1)==0){
s.insert(a-1);
}else if(s.count(a)==0){
s.insert(a);
}else{
s.insert(a+1);
}
}
}
// for(auto &a:s){
// cout<<a<<" ";
// }
// cout<<endl;
cout<<(int)s.size()<<endl;
return 0;
}1263A - Sweet Problem | 1332B - Composite Coloring |
254A - Cards with Numbers | 215A - Bicycle Chain |
1288B - Yet Another Meme Problem | 1201C - Maximum Median |
435A - Queue on Bus Stop | 1409B - Minimum Product |
723B - Text Document Analysis | 1471C - Strange Birthday Party |
1199A - City Day | 1334A - Level Statistics |
67B - Restoration of the Permutation | 1734A - Select Three Sticks |
1734B - Bright Nice Brilliant | 357B - Flag Day |
937A - Olympiad | 1075A - The King's Race |
1734C - Removing Smallest Multiples | 1004C - Sonya and Robots |
922A - Cloning Toys | 817A - Treasure Hunt |
1136B - Nastya Is Playing Computer Games | 1388A - Captain Flint and Crew Recruitment |
592B - The Monster and the Squirrel | 1081A - Definite Game |
721C - Journey | 1400A - String Similarity |
1734E - Rectangular Congruence | 1312D - Count the Arrays |