This is the problem:
Develop a recursive function f() to display the sequence:
1 2 3 4 5...i (i-1) (i-2)...2 1
in a text field when f(1,i) is called.
We are not allowed to use loops, global variables, or arrays. We also have to be able to make it work for any starting point and ending point. ex:
f(2,5)=2 3 4 5 4 3 2.
I am completely stumped. Please at least give me a hint.
Big hint:
f(2,5) = 2 + f(3,5) + 2;
f(3,5) = 3 + f(4,5) + 3;
f(4,5) = 4 + f(5,5) + 5;
f(5,5) = 5;
so
{ a + f(a+1,b) + a if a<b
f(a,b) = {
{ a if a==b
Now try to code it.
Assuming the function must return a string, here's a hint:
The base case is when the sequence has only one number in it, in which you return a sequence with that number. In other cases, you call the function recursively with the first argument one less, then put the first argument on the beginning and the end of the result.
Use 2 recursive functions. The code below is not tested - it is intended to serve as a hint
void printSequenceForGivenNumber(int i)
{
printNextBiggerNumber(i, maximum);
printNextSmallerNumber(maximum - 1)
}
void printNextBiggerNumber(int input, int maximum)
{
if(input <= maximum)
{
System.out.print(input + " ");
printNextBiggerNumber(input + 1, maximum);
}
}
void printNextSmallerNumber(int input)
{
if (current > = 1)
{
System.out.print(input + " ");
printNextSmallerNumber(input - 1);
}
}
This example also handles if the the first argument is greater than the second
printUpAndDown(1, 5) = 1 2 3 4 5 4 3 2 1
printUpAndDown(5, 1) = 5 4 3 2 1 2 3 4 5
printUpAndDown(5, 5) = 5
public static void printUpAndDown(int i, int j)
{
System.out.print(i + " ");
if (i == j) return;
int intToPass = (i > j) ? i - 1 : i + 1;
printUpAndDown(intToPass, j);
System.out.print(i + " ");
}
We are not allowed to use loops, global variables, or arrays.: Are you allowed to code? Start it and bring here the code where you end at, then someone can surely help you finish itf(2,5)is2 3 4 5 4 3 2 1and notf(2,5)=2 3 4 5 4 3 2?