//Yel #include <bits/stdc++.h> #define fast ios_base::sync_with_stdio(false); cin.tie(0); #define pb push_back #define np next_permutation #define YES {cout<<"YES";rt} #define NO {cout<<"NO";rt;} #define Yes cout<<"Yes"; #define No cout<<"No"; #define rep(st,pl,en) for(ll i=st;i<=en;i+=pl) #define ll long long #define sz size() #define pi pair<int,int> #define F first #define S second #define dot fixed<<setprecision #define str string #define all(x) x.begin(),x.end() #define allr(x) x.rbegin(),x.rend() #define rt return #define dl long double #define Pi 3.141592653589793238462643383279 #define cnl cout<<'\n'; #define nl '\n' #define int ll #define co continue #define open freopen("slalom.in","r",stdin);freopen("slalom.out","w",stdout); using namespace std; const int inf=1e18,mod=1e9+7,N=5e5+9; int res=0; vector <string> v[5]; void abdu_abi(){ int n,k; cin>>n>>k; for(int i=1;i<=n;i++){ str s; cin>>s; //sec=s; for(int j=1;j<=4;j++){ str sec=s; sec.erase(sec.begin()+j-1); //cout<<sec<<nl; v[j].pb(sec); } } int ans=0; for(int k=1;k<=4;k++){ int cnt=1; sort(all(v[k])); for(int i=1;i<v[k].sz;i++){ if(v[k][i]==v[k][i-1]){ cnt++; } else{ ans+=cnt*(cnt-1)/2; cnt=1; } } ans+=cnt*(cnt-1)/2; } cout<<ans; } main(){ //open; fast; int t=1; //cin>>t; while(t--){ abdu_abi(); } }

pin.cpp:63:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   63 | main(){
      | ^~~~