logo CodeStepByStep logo

Main Page → Exercises → C++ → Solve an Exercise

travel

Language/Type: C++ recursion exhaustive search

Write a recursive function named travel that accepts integers x and y as parameters and uses recursive backtracking to print all solutions for traveling in the 2-D plane from (0, 0) to (x, y) by repeatedly using one of three moves:

  • East (E): move right 1 (increase x)
  • North (N): move up 1 (increase y)
  • Northeast (NE): move up 1 and right 1 (increase both x and y)

The following diagram shows one such path to the point (5, 3).
travel

You may assume that the x/y values passed are non-negative. If x and y are both 0, print a blank line.

The table below shows several calls to your function and the lines of output. Your lines can appear in any order; our output shown tries the possibilities in the order listed above: East, then North, then Northeast.

Call Output Call Output 
travel(1, 2);
 
E N N
N E N
N N E
N NE
NE N

travel(2, 2);
 
E E N N
E N E N
E N N E
E N NE
E NE N
N E E N
N E N E
N E NE
N N E E
N NE E
NE E N
NE N E
NE NE

travel(2, 1);
 
E E N
E N E
E NE
N E E
NE E

travel(1, 1);
 
E N
N E
NE

Constraints: Your solution must be recursive. Do not use any loops in solving this problem.

Function: Write a C++ function as described, not a complete program.

You must log in before you can solve this problem.

Log In

Need help?

Stuck on an exercise? Contact your TA or instructor.

If something seems wrong with our site, please

Is there a problem? Contact us.