Sudoku is a puzzle of 9 x 9 grid of numbers and spaces such that the spaces are to be filled by the user. The rules are that each row, column and nine 3 x 3 sub grids must contain unique numbers 1 to 9.

My research has led me to use binary search trees and stochastic search. The latter involves:

1) Assign random numbers to cells marked as zero.

2) Evaluate number of errors.

3) Shuffle inserted numbers to reduce errors to zero.

Unfortunately, the functions, to generate random numbers, provided by the C programming language: srand and rand result in many repeats. I researched solution via new project RNG (Random Number Generator).

I implemented this solution into the code for Sudoku. Written C code to create and solve a Sudoku.

The plethora of C code is avoidance of a brute force approach!