You have seen it in the news papers, you have seen it in the magazines or in the web sites, you might have sat hours ‘n hours to solve it. Yes, it is the king of all number puzzles, it is “SUDOKU”.
We bring to you the ultimate solution for all your struggles, The SUDOKU Solver.
As [...]

Lexical analyzer converts stream of input characters into a stream of tokens. The different tokens that our lexical analyzer identifies are as follows:
KEYWORDS: int, char, float, double, if, for, while, else, switch, struct, printf, scanf, case, break, return, typedef, void
IDENTIFIERS: main, fopen, getch etc
NUMBERS: positive and negative integers, positive and negative floating point numbers.
OPERATORS: +, [...]