| # | Time | Username | Problem | Language | Result | Execution time | Memory | 
|---|---|---|---|---|---|---|---|
| 1118785 | Minbaev | PIN (CEOI10_pin) | C++17 | 0 ms | 0 KiB | 
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
 
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("Ofast,unroll-loops")
 
using namespace std;
using namespace __gnu_pbds;
 
#define pb 		push_back
#define all(x) 	x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define f 		first
#define s 		second
#define int 	long long
#define ll 		long long
#define pii 	pair<int,int>
#define ar 		array
#define mps		make_pair
 
template<class T>bool umax(T &a,T b){if(a<b){a=b;return true;}return false;}
template<class T>bool umin(T &a,T b){if(b<a){a=b;return true;}return false;}
 
template<class T> using ste = tree<T, null_type, less_equal<T>,
rb_tree_tag, tree_order_statistics_node_update>;
 
const int inf = 3e18 + 7;
const int mod = 1e9 + 9;
const int N = 2e5 + 5;
const int md = 998244353;
 
int binpow(int a, int b, int m){
	if(b == 0)return 1;
	if(b % 2 == 0){
		int c = binpow(a,b/2,m);
		return (c*c)%m;
	}
	return (binpow(a,b-1,m)*a)%m;
}
 
int divi(int a, int b, int m){
	return (a*(binpow(b,m-2, m)))%m;
}
 
int n,m,k,q;
void solve(){
 
	cin >> n >> k;
	vector<string>v(n);
	for(auto &to:v)cin >> to;
	
	int res = 0;
	if(n <= 2000){
		for(int i = 0;i<n;i++){
			for(int j = i+1;j<n;j++){
				int cnt = 0;
				for(int l = 0;l<4;l++){
					if(v[i][l] != v[j][l])cnt += 1;
				}
				if(cnt == k)res += 1;
			}
		}
	}
	else{
		map<string,int>mp;
		for(auto to:v)mp[to] += 1;
		
		for(int i = 0;i<n;i++){
			for(int j = 0;j<4;j++){
				char ch = v[i][j];
				for(int l = 0;l<=9;l++){
					char rep = (l+'0');
					if(rep == ch)continue;
					v[i][j] = rep;
					res += mp[v[i]];
				}
				v[i][j] = ch;
			}
		}
		rse /= 2;
	}
	
	
	cout << res << "\n";
	
	
	
	
	
	
	
	
	
 	
 	
 	
 	
 	
 	
}
/*
 
*/
 signed main()
{
//	freopen("seq.in", "r", stdin);
//  freopen("seq.out", "w", stdout);
	ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);
	int tt=1;//cin>>tt;
	while(tt--)solve();
 
}
