Codeforces (268A) Problem Solution

 A - Games

Problem Link: [Codeforces 268A##link##]

• [tab]
• C++

• #include<bits/stdc++.h>
  #define ll long long
  using namespace std;
  int main()
  {
      ll n;
      cin>>n;
      ll a[n],b[n];
      for(ll i=0;i<n;i++)
      {
          cin>>a[i]>>b[i];
      }
      ll cnt=0;
      for(ll i=0;i<n;i++)
      {
          for(ll j=0;j<n;j++)
          {
              if(a[i]==b[j])
                  cnt++;
          }
      }
      cout<<cnt<<endl;
  }

• Python3

• n=int(input())
  w=0
  list1=[]
  list2=[]
  for i in range(n):
      a,b=map(lambda x:int(x),input().split())
      list1.append(a)
      list2.append(b)
  for i in list1:
      k=0
      while k<len(list2):
          if i == list2[k]:
              w+=1
          k+=1
  print(w)

• JAVA

• import java.util.HashMap;
  import java.util.Map;
  import java.util.Scanner;
   
  public class Games {
      public static void main(String[] args) {
          Scanner in = new Scanner(System.in);
          int n = Integer.parseInt(in.nextLine()), result = 0;
          int[] home = new int[n];
          int[] guest = new int[n];
   
          for(int i = 0; i < n; i++) {
              home[i] = in.nextInt();
              guest[i] = in.nextInt();
          }
   
          for(int i = 0; i < n; i++)
              for(int j = 0; j < n; j++)
                  if(home[i] == guest[j])
                      result++;
   
          System.out.println(result);
      }
  }