S2Q2 · Abbreviate Initials and Sort (Last, F.M. Format)¶

⚡ Quick Reference

Type: Full I/O problem

Core idea: split each name, last part = surname, all other parts = initials joined without spaces; format as "Last, F.M.", sort, print.

n = int(input())
results = []
for _ in range(n):
    parts    = input().split()
    last     = parts[-1]
    initials = "".join(p[0] + "." for p in parts[:-1])
    results.append(f"{last}, {initials}")

for name in sorted(results):
    print(name)

Key rules: - Last name → parts[-1] - All other parts → first letter + ".", concatenated with no spaces - Format: "LastName, F.M." - Sort alphabetically and print

Problem Statement¶

Problem (I/O type)

Read n full names. Convert each to "Last, Initials." format and print sorted alphabetically.

Example:

Input

3
John Doe
Alice Johnson
Bob Alan Rickman

Output

Doe, J.
Johnson, A.
Rickman, B.A.

Understanding the format¶

"John Doe"         → parts = ["John", "Doe"]
                     last = "Doe",  initials = "J."
                     → "Doe, J."

"Alice Johnson"    → parts = ["Alice", "Johnson"]
                     last = "Johnson",  initials = "A."
                     → "Johnson, A."

"Bob Alan Rickman" → parts = ["Bob", "Alan", "Rickman"]
                     last = "Rickman",  initials = "B." + "A." = "B.A."
                     → "Rickman, B.A."

Key difference from Set 1 S2Q2: the output format here is "Last, Initials." not "Initials. Last", and multiple initials are joined without a space between them.

Tracing the example¶

Full name	`last`	`parts[:-1]`	`initials`	Result
`"John Doe"`	`"Doe"`	`["John"]`	`"J."`	`"Doe, J."`
`"Alice Johnson"`	`"Johnson"`	`["Alice"]`	`"A."`	`"Johnson, A."`
`"Bob Alan Rickman"`	`"Rickman"`	`["Bob","Alan"]`	`"B.A."`	`"Rickman, B.A."`

Sorted: Doe, Johnson, Rickman ✓

Solution approaches¶

PythonicExplanatoryUsing list comprehension + mapUsing lambda

n = int(input())
results = []
for _ in range(n):
    parts    = input().split()
    last     = parts[-1]
    initials = "".join(p[0] + "." for p in parts[:-1])
    results.append(f"{last}, {initials}")

for name in sorted(results):
    print(name)

n = int(input())
results = []

for _ in range(n):
    parts = input().split()
    last  = parts[-1]

    # Build initials - no spaces between them
    initials = ""
    for part in parts[:-1]:
        initials += part[0] + "."

    formatted = last + ", " + initials
    results.append(formatted)

results.sort()
for name in results:
    print(name)

n = int(input())

def format_name(full_name):
    parts    = full_name.split()
    last     = parts[-1]
    initials = "".join(p[0] + "." for p in parts[:-1])
    return f"{last}, {initials}"

names   = [input() for _ in range(n)]
results = sorted(map(format_name, names))
print("\n".join(results))

n = int(input())
fmt = lambda name: (lambda p: f"{p[-1]}, {''.join(x[0]+'.' for x in p[:-1])}")(name.split())
results = sorted(fmt(input()) for _ in range(n))
for name in results:
    print(name)

Key takeaways¶

01

"".join() - no spaces between initials

"".join(p[0] + "." for p in parts[:-1]) concatenates all initials without separators. "B." + "A." = "B.A." not "B. A." - the dot is part of each initial, not a separator.

02

Format is "Last, Initials." not "Initials Last"

This question uses surname-first format with a comma separator - different from the Set 1 version which used initials-first. Read the output format carefully each time.

03

Sort the formatted strings, not the originals

Format all names first, then sort. Sorting happens on the "Last, Initials." strings - alphabetical order by surname, which is what we want.