Java Study Questions

1. Look at the code, what special do you find?

The return value type is not the same as the parameter type.

2. Solving the questions of the Nottingham Tower

Code:

public class towersofhanoi{
Used to move a plate recursively
public static void Solvetowers (int disks, int sourcepeg,
int destinationpeg, int temppeg)//The first parameter is the total number of plates, the second parameter means the starting disk, the third parameter is the target disk, the fourth parameter is the auxiliary disk
{
Only one plate, moving directly from the starter tray to the target disk
if (disks = = 1)
{
System.out.print (sourcepeg+ "--" +destinationpeg+ "");
Return
}

Move the N-1 plate from the starter tray to the auxiliary tray
Solvetowers (Disks-1, Sourcepeg, Temppeg, destinationpeg);

The last plate on the starter plate is moved to the target disk.
System.out.print (sourcepeg+ "--" +destinationpeg+ "");

On the auxiliary plate, move the N-1 plate to the target plate.
Solvetowers (Disks-1, Temppeg, Destinationpeg, sourcepeg);
}//End

public static void Main (string[] args) {
int startpeg = 1; Start disk
int endpeg = 3; Target Disk
int temppeg = 2; Auxiliary disk
int totaldisks = 4; Total Plates
Solvetowers (Totaldisks, Startpeg, Endpeg, temppeg);
}
}

Program Design ideas: Define a function for recursive operation, the total plate is n,1 for the starting disk, 2 for the auxiliary disk, 3 for the target disk, the first 1 on the N-1 plate moved to 2, then the last plate 1 on the 3, and finally the 2 on the N-1 plate moved to 3, and then recursion, until completed.

3. Determine whether a string is a palindrome by recursion

A palindrome is the same as reading and reading the opposite, such as "I am who I am", First judge 1th and Nth, and then judge the 2nd and the first N-1 ... By recursion, when there is only one or 0 characters at the end, the program terminates and ends.

Java Study Questions