Unlike most languages, Python evaluates a as it would be done in mathematics, actually comparing the three
numbers, as opposed to comparing the boolean a to
c. The correct way to write this in C (and many
others) would be a.

この課題では、Python
/直感的な表現から任意の長さの比較チェーンを展開し、他言語での記述方法まで拡張することが課題です。

仕様

• Your program will have to handle the operators:
==, !=, <, >, <=, >=.
• The input will have comparison chains using only
  integers.
• Don’t worry about the trueness of any of the
  comparisons along the way, this is purely a parsing/syntactical
  challenge.
• The input won’t have any whitespace to prevent answers
  that trivialize parsing by splitting on spaces.
• However, your output may have a single space
  surrounding either just the &&‘s, or both the
  comparison operators and the &&‘s, or neither, but
  be consistent.

テストケース

Input                  Output
---------------------------------------------------------------

3<4<5                  3<4 && 4<5
3<4<5<6<7<8<9          3<4 && 4<5 && 5<6 && 6<7 && 7<8 && 8<9
3<5==6<19              3<5 && 5==6 && 6<19
10>=5<7!=20            10>=5 && 5<7 && 7!=20
15==15==15==15==15     15==15 && 15==15 && 15==15 && 15==15

This is code-golf, so shortest code in bytes
wins!