Last updated on October 5th, 2024 at 04:21 pm

Here, We see Friend Requests II: Who Has the Most Friends LeetCode Solution. This Leetcode problem is done in many programming languages like C++, Java, JavaScript, Python, etc. with different approaches.

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Friend Requests II: Who Has the Most Friends LeetCode Solution

Problem Statement

(requester_id, accepter_id) is the primary key (combination of columns with unique values) for this table. This table contains the ID of the user who sent the request, the ID of the user who received the request, and the date when the request was accepted.

Write a solution to find the people who have the most friends and the most friends number.

The test cases are generated so that only one person has the most friends.

The result format is in the following example.

Example 1:
Input:

Output:

Explanation: The person with id 3 is a friend of people 1, 2, and 4, so he has three friends in total, which is the most number than any others.

1. Friend Requests II: Who Has the Most Friends LeetCode Solution MySQL

with base as(
  select 
    requester_id id 
  from 
    RequestAccepted 
  union all 
  select 
    accepter_id id 
  from 
    RequestAccepted
) 
select 
  id, 
  count(*) num 
from 
  base 
group by 
  1 
order by 
  2 desc 
limit 
  1

2. Friend Requests II: Who Has the Most Friends LeetCode Solution Pandas

import pandas as pd
def most_friends(request_accepted: pd.DataFrame) -> pd.DataFrame:
    req = request_accepted.requester_id.value_counts().reset_index().rename(columns ={'requester_id':'id'})
    acc = request_accepted.accepter_id.value_counts().reset_index().rename(columns ={'accepter_id':'id'})
    df = req.merge(acc, on ='id', how ='outer', suffixes=('_req','_acc')).fillna(0)
    return df.assign(num = df.count_req + df.count_acc)[['id','num']].query('num == num.max()')