func_code_string: #include <bits/stdc++.h>   using namespace std;   struct less_key {     bool operator()(pair<double, int64_t> p1, pair<double, int64_t> p2) {       return (p1.first > p2.first) ||              ((p1.first == p2.first) && (p1.second < p2.second));     }   };   struct pair_hash {     std::size_t operator()(const pair<int64_t, int64_t>& k) const {       return static_cast<size_t>(k.first ^ k.second);     }   };   const int64_t mod = 100000000007ll;   const int64_t inf = 10000000000000007ll;   const double eps = 0.00000001;   int64_t n, k;   string s;   int64_t amin[256];   int64_t amax[256];   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cin >> n >> k;     cin >> s;     for (int64_t i = 0; i < s.size(); i++) {       if (!amin[s[i]]) {         amin[s[i]] = i + 1;       }       amax[s[i]] = i + 1;     }     set<pair<int64_t, int64_t> > q;     for (int64_t i =  A ; i <=  Z ; i++) {       if (amin[i]) {         q.insert({amin[i], 0});         q.insert({amax[i], 1});       }     }     int64_t z = 0;     for (auto i : q) {       if (i.second) {         z--;       } else {         z++;       }       if (z > k) {         cout <<  YES  << endl;         return 0;       }     }     cout <<  NO  << endl;     return 0;   }   