Question

What will be the lexicographical order of permutations formed from the array arr={1,2,3}?

(a) {{2,1,3},{3,2,1},{3,1,2},{2,3,1},{1,2,3},{1,3,2}}

(b) {{1,2,3},{1,3,2},{2,3,1},{2,1,3},{3,2,1},{3,1,2}}

(c) {{1,2,3},{1,3,2},{2,1,3},{2,3,1},{3,1,2},{3,2,1}}

(d) {{2,1,3},{3,1,2},{3,2,1},{2,3,1},{1,2,3},{1,3,2}}

I got this question in an interview.

Enquiry is from Number Theory topic in chapter Number Theory of Data Structures & Algorithms II

Answer 1

The correct option is (c) {{1,2,3},{1,3,2},{2,1,3},{2,3,1},{3,1,2},{3,2,1}}

Explanation: The number of permutations for the problem will be 6 according to the formula 3P3. When ordered in lexicographical manner these will be {{1,2,3},{1,3,2},{2,1,3},{2,3,1},{3,1,2},{3,2,1}}.