Given an integer sequence, say {6, 1, 3, 4, 5, 2}, can we sort the sequence by keeping swapping the first number with its two neighbors: the second number and the last number ?
For example, Swap the first number 6 and with the last number 2 to get {2, 1, 3, 4, 5, 6}, and then swap the first number 2 and the second number 1 to get {1, 2, 3, 4, 5, 6}, and we get the sequence sorted.
In function.h we define a class called SwapSort. A constructor and member functions show_solutions, solve, isSorted are implemented. Your task is to complete the implementation of extend function:
1. set<State> extend(State s);
A State is defined as using State = vector<int>;
For some State s, we may extend it by swapping the first number with the second one, or swapping the first number with the last one. Therefore, from State s we may generate two new states, and insert them into a set.
Note:
1. no duplicate states are allowed in a solution.
2. For OJ submission, you may choose c++ 11 as your compiler.
You need to implement the function in function.cpp
An integer sequence, separated by spaces. End by EOF.
The output will be generated by function.h