Fill Matrix

Problem Overview

• Fill an N×N matrix with integers 1 to N^2 so each row, column, and both main diagonals have the same sum.
• Input: integer N; Output: an N×N matrix satisfying the equal-sum property; constraints are unspecified.
• Domain: matrix construction and combinatorics, similar to puzzle-style grid arrangement.
• From Google interviews; a classic coding interview problem and common interview question.