Project Euler Problem 22

Project Euler Problem 22

Solution

Answer: 871198282

We must:

1. Read the list of names.
2. Sort them alphabetically.
3. For each name:

• Compute its alphabetical value (A=1, B=2, ..., Z=26)
• Multiply by its 1-based position in the sorted list.

4. Sum all scores.

For example:

• COLIN
• Value = 3+15+12+9+14 = 53
• Position = 938
• Score = 938 × 53 = 49714

The computation is straightforward once the file is parsed correctly.

Python code:

from string import ascii_uppercase

# Build letter values
value = {c: i + 1 for i, c in enumerate(ascii_uppercase)}

# Read and parse names
with open("0022_names.txt") as f:
    names = f.read().replace('"', '').split(',')

# Sort alphabetically
names.sort()

# Compute total score
total = 0

for i, name in enumerate(names, start=1):
    name_value = sum(value[ch] for ch in name)
    total += i * name_value

print(total)

Tracing the logic:

• The file contains 5163 names.
• Sorting matches the Project Euler specification.
• Each score is computed exactly once.
• Summing all scores yields the known correct Project Euler result.

Answer: 871198282