func_code_string: #include <bits/stdc++.h>   #define int long long int   #define us unsigned int   #define null 0   #define m_p make_pair   #define f_i first   #define s_e second   #define p_b push_back      using namespace std;         void IOS()   {       ios_base::sync_with_stdio(false);       cin.tie(NULL);   }                  int32_t main()   {       IOS();   int test;   cin>>test;   while(test--)   {       int n;       cin>>n;       string s;       cin>>s;       map<char,int> mp;       bool flag=true;          for(int i=0;i<n;i++)       {           if(mp.find(s[i])==mp.end())           {               mp[s[i]]=i;           }           else if(i-mp[s[i]]>1)           {               flag=false;               break;           }           mp[s[i]]=i;       }          if(flag)       {           cout<< YES <<endl;       }          else       {           cout<< NO <<endl;       }   }      }                                                         