#0297

Accounts Merge

MediumDSA28 min20 XP

Problem

Each account is [name, email1, email2, ...]. Merge accounts that share emails. Return sorted merged accounts as [name, sorted emails...], sorted by name then first email.

Why This Matters

Accounts Merge is a realistic union-find problem: entities connect through shared identifiers.

Function Signature

def accounts_merge(accounts):

Examples

Example 1

Inputaccounts = [["John","a@mail","b@mail"],["John","b@mail","c@mail"],["Mary","m@mail"]]

Output[["John", "a@mail", "b@mail", "c@mail"], ["Mary", "m@mail"]]

The two John accounts share b@mail, so all three John emails merge.

Constraints

Return the exact requested value.
Handle edge cases cleanly.
Use the intended DSA pattern when brute force would scale poorly.

CodePython

def accounts_merge(accounts):
    """
    Input example: accounts = [["John","a@mail","b@mail"],["John","b@mail","c@mail"],["Mary","m@mail"]]
    Return: [["John", "a@mail", "b@mail", "c@mail"], ["Mary", "m@mail"]]
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return []

def accounts_merge(accounts):
    """
    Input example: accounts = [["John","a@mail","b@mail"],["John","b@mail","c@mail"],["Mary","m@mail"]]
    Return: [["John", "a@mail", "b@mail", "c@mail"], ["Mary", "m@mail"]]
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return []

Visible browser tests run here when available.

Testcases2 visible / 3 hidden categories

Shared email merge

InputJohn shares b@mail

Expectedmerged John and Mary

Shared email connects accounts into one component.

Separate same name

Inputsame name no shared email

Expectedtwo separate rows

Same name alone is not enough to merge.

Hidden Test Categories

chain of shared emailsmultiple namesemail order shuffled