User Network Reach Percentage

HARD30 pts

A community analytics platform stores pairwise user connections in a friendship table.

Table: Friends

user1: first user in a friendship pair
user2: second user in a friendship pair

Each row means user1 and user2 are connected. Treat friendships as undirected edges.

Popularity percentage definition:

Let total_users be the count of distinct users appearing in either user1 or user2.
Let friend_count(u) be the number of distinct users directly connected to user u.
popularity(u) = (friend_count(u) / total_users) * 100
Round to 2 decimal places using HALF_UP behavior.

Task: For every distinct user in the table, return:

user1
percentage_popularity

Output requirements:

Return one row per distinct user.
Sort rows by user1 in ascending order.
If Friends has no rows, return an empty result.

Supported submission environments:

SQL (SQLite 3.27.2)
Pandas (Python)

Example

Input

Friends:
| user1 | user2 |
|-------|-------|
| 2     | 1     |
| 1     | 3     |
| 4     | 1     |
| 1     | 5     |
| 1     | 6     |
| 2     | 6     |
| 7     | 2     |
| 8     | 3     |
| 3     | 9     |

Output

[
  {"user1":1,"percentage_popularity":55.56},
  {"user1":2,"percentage_popularity":33.33},
  {"user1":3,"percentage_popularity":33.33},
  {"user1":4,"percentage_popularity":11.11},
  {"user1":5,"percentage_popularity":11.11},
  {"user1":6,"percentage_popularity":22.22},
  {"user1":7,"percentage_popularity":11.11},
  {"user1":8,"percentage_popularity":11.11},
  {"user1":9,"percentage_popularity":11.11}
]

Explanation

There are 9 distinct users total. User 1 has five distinct friends, so percentage is (5/9)*100 = 55.56. The same rule is applied to every user.

Example

Input

Friends:
| user1 | user2 |
|-------|-------|
| 10    | 20    |
| 20    | 30    |
| 20    | 40    |
| 50    | 20    |

Output

[
  {"user1":10,"percentage_popularity":20.0},
  {"user1":20,"percentage_popularity":80.0},
  {"user1":30,"percentage_popularity":20.0},
  {"user1":40,"percentage_popularity":20.0},
  {"user1":50,"percentage_popularity":20.0}
]

Explanation

There are 5 users total. User 20 is connected to four users, so percentage is 80.00.

Example

Input

Friends:
[]

Output

[]

Explanation

No rows means no users to evaluate, so the result is empty.

Accepted0/0·0% Acceptance

Constraints

0 <= number of rows in Friends <= 200000
1 <= user1, user2 <= 1000000000
user1 != user2
(user1, user2) pairs are unique
At most one row exists for each unordered friendship pair
Popularity denominator is the count of distinct users from both columns
Return exactly two columns: user1, percentage_popularity
Round percentage to exactly 2 decimal places using HALF_UP behavior
If Friends is empty, return an empty result set
For SQL submissions, use SQLite 3.27.2 semantics
For Pandas submissions, return a DataFrame with columns: user1, percentage_popularity

Code

Visualizer

Solutions

14px

Test Cases3

Results

Submissions

Friends =

[{"user1":2,"user2":6},{"user1":2,"user2":1},{"user1":3,"user2":9},{"user1":7,"user2":2},{"user1":1,"user2":3},{"user1":8,"user2":3},{"user1":1,"user2":6},{"user1":4,"user2":1},{"user1":1,"user2":5}]

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