This puzzle bears a similarity to hidoku, and is of unclear origin.
Puzzle and Goal
An unsolved puzzle consists of a 5x5 grid. Around the edges of the grid are the letters B to Y. The letter A has been placed.
The goal is to fill in all the cells so that all letters A to Y appear exactly once.
The solved grid must satisfy the following conditions:
Each letter must appear in the row, column, or diagonal corresponding to its clue.
Each letter must be a neighbor to the letter that comes before and after it (A and Y don't have to neighbor each other, though).
In "1 to 25", the numbers 1 to 25 are used instead of the letters A to Y.
1 to 25; ABC Pfad