문제
풀이
#include <iostream>
#include <unordered_map>
using namespace std;
bool solve(void) {
int n; cin >> n;
unordered_map<int, bool> mp;
while (n--) {
int x; cin >> x;
mp[x] = true;
}
for (auto [k, v] : mp) {
if (mp.find(k+3) != mp.end() && mp.find(k+6) != mp.end()) return true;
}
return false;
}
int main(void) {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cout << (solve() ? "Yes" : "No");
return 0;
}